Signaling for inactive small data transmission without path switching

ABSTRACT

Techniques, systems, and devices to support small data transfers are described. A first node, such as a gNodeB or an eNodeB, can perform operations that include receiving a resume request from a user equipment (UE) that is in an inactive state, the resume request including a small data indication, where context information for the UE resides at a second node; transmitting a retrieve UE context request to the second node, the retrieve UE context request including the small data indication; receiving a UE context response from the second node; transmitting, by the first node, a resume response to the UE to cause the UE to switch to a connected state; processing uplink data from the UE; and transmitting a release message to the UE to cause the UE to switch to the inactive state. The release message can be based on RRC release information received from the second node.

CROSS-REFERENCE TO RELATED APPLICATION

This disclosure claims the benefit of the priority of U.S. ProvisionalPatent Application No. 62/820,766, entitled “SIGNALING FOR INACTIVESMALL DATA TRANSMISSION WITHOUT PATH SWITCHING” and filed on Mar. 19,2019. The above-identified application is incorporated herein byreference in its entirety.

TECHNICAL FIELD

This disclosure relates generally to signaling in wireless communicationsystems.

BACKGROUND

Wireless communication systems are rapidly growing in usage. Further,wireless communication technology has evolved from voice-onlycommunications to also include the transmission of data, such asInternet and multimedia content, to a variety of devices. To accommodatea growing number of devices communicating, many wireless communicationsystems share the available communication channel resources amongdevices. Further, Internet-of-Thing (IoT) devices are also growing inusage and can coexist with user devices in various wirelesscommunication systems such as cellular networks.

SUMMARY

Techniques, systems, and devices to support small data transfers aredescribed. Nodes, such as a gNodeB or an eNodeB, can perform operationsthat include receiving, by a first node, a resume request from a userequipment (UE) that is in an inactive state, the resume requestincluding a small data indication, wherein context information for theUE resides at a second node; transmitting, by the first node, a retrieveUE context request to the second node, the retrieve UE context requestincluding the small data indication; receiving, by the first node, a UEcontext response from the second node; receiving, by the first node,Radio Resource Control (RRC) release information from the second node;transmitting, by the first node, a resume response to the UE to causethe UE to switch to a connected state from the inactive state;processing, by the first node, uplink data from the UE; andtransmitting, by the first node, a release message to the UE to causethe UE to switch to the inactive state from the connected state. Therelease message can be based on the RRC release information receivedfrom the second node. Small data transmissions can be in the uplink(UL), downlink (DL), or both.

This and other implementations can include one or more of the followingfeatures. The first and second nodes can be of different types. Forexample, the first node can be a gNB, and the second node can be an eNB.The first node can cause a transfer of a UE context to the first nodefrom the second node. The UE context can be transferred back to thesecond node after completion of a data transfer. Processing the uplinkdata from the UE can include receiving the uplink data from the UE; andforwarding the uplink data to a device that provides a User PlaneFunction (UPF).

In some implementations, the UE context response comprises the RRCrelease information. In some implementations, the first node transmits aUE context release confirm message to the second node to stop datatransfer and to cause a UE context to transfer to the second node. Insome implementations, the RRC release information comprises one or moreRRC release configuration parameters, and the first node is configuredto generate the release message based on the one or more RRC releaseconfiguration parameters. In some implementations, the release messageis generated by the second node. In some implementations, the RRCrelease information includes the release message to be transmitted tothe UE.

In some implementations, the UE context response includes an indicationthat a path switch will not be perform. The first node can transmit a UEcontext release request to the second node; and receive a UE contextrelease response from the second node. The UE context release responsecan include the RRC release information. In some implementations, theRRC release information includes one or more RRC release configurationparameters, and the first node can generate the release message based onthe one or more RRC release configuration parameters. In someimplementations, the release message is generated by the second node,and the RRC release information includes the release message to betransmitted to the UE.

A device such as a UE can include circuitry to communicate with one ormore nodes such as a first node; and a processor configured to performoperations. The operations can include transmitting, while in aninactive state, a resume request message to the first node, the resumerequest including a small data indication; receiving a resume responsecontaining an instruction to switch to a connected state from theinactive state; transitioning to the connected state in response to theresume response; transmitting uplink data to the first node; receiving arelease message containing an instruction to switch to the inactivestate from the connected state; and transitioning to the inactive statein response to the release message. The resume request message can causethe second node to transfer device context information to the firstnode.

The details of one or more implementations are set forth in theaccompanying drawings and the description below. Other features andadvantages will be apparent from the description and drawings, and fromthe claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates an example of a wireless communication system.

FIG. 2 illustrates an example architecture of a system including a corenetwork.

FIG. 3 illustrates another example architecture of a system including acore network.

FIG. 4 illustrates an example of infrastructure equipment.

FIG. 5 illustrates an example of a platform or device.

FIG. 6 illustrates example components of baseband circuitry and radiofront end circuitry.

FIG. 7 illustrates example components of cellular communicationcircuitry.

FIG. 8 illustrates example protocol functions that may be implemented inwireless communication systems.

FIG. 9 illustrates an example of a computer system.

FIG. 10 illustrates an example of a resume procedure for a small datatransmission.

FIG. 11 illustrates an example of a message exchange initiated by a RRCresume request containing a small data indication.

FIG. 12 illustrates another example of a message exchange initiated by aRRC resume request containing a small data indication.

FIG. 13 illustrates a flowchart of an example of a process associatedwith the handling of a small data transmission by different nodes withina wireless communication system.

FIG. 14 illustrates a flowchart of an example of a process associatedwith a small data transmission request by a UE.

FIG. 15 illustrates a flowchart of an example of a process associatedwith the handling of a small data transmission by different nodes withina wireless communication system.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

In many wireless communication systems, including long-term evolution(LTE) and fifth generation new radio (5G NR) cellular networks, a userequipment (UE) may need to transmit a small amount of data to a basestation (BS) within the network. For example, in a Cellular Internet ofThings (CIoT), a sensor device equipped with a communication device suchas a user equipment (UE) can take a sensor reading and then transmit thereading, or a batch of readings, to the BS. Other examples includetracking devices for Mobile Originated (MO) and Mobile Terminated (MT)use cases that report positions via a BS. The present disclosuredescribes, among other things, signaling mechanisms to support frequentsmall data transmission without path switching between different basestations.

FIG. 1 illustrates an example of a wireless communication system 100.For purposes of convenience and without limitation, the example system100 is described in the context of the LTE and 5G NR communicationstandards as defined by the Third Generation Partnership Project (3GPP)technical specifications. However, other types of wireless standards arepossible.

The system 100 includes UE 101 a and UE 101 b (collectively referred toas the “UEs 101”). In this example, the UEs 101 are illustrated assmartphones (e.g., handheld touchscreen mobile computing devicesconnectable to one or more cellular networks). In other examples, any ofthe UEs 101 can include other mobile or non-mobile computing devices,such as consumer electronics devices, cellular phones, smartphones,feature phones, tablet computers, wearable computer devices, personaldigital assistants (PDAs), pagers, wireless handsets, desktop computers,laptop computers, in-vehicle infotainment (IVI), in-car entertainment(ICE) devices, an Instrument Cluster (IC), head-up display (HUD)devices, onboard diagnostic (OBD) devices, dashtop mobile equipment(DME), mobile data terminals (MDTs), Electronic Engine Management System(EEMS), electronic/engine control units (ECUs), electronic/enginecontrol modules (ECMs), embedded systems, microcontrollers, controlmodules, engine management systems (EMS), networked or “smart”appliances, machine-type communications (MTC) devices,machine-to-machine (M2M) devices, Internet of Things (IoT) devices, orcombinations of them, among others.

In some implementations, any of the UEs 101 may be IoT UEs, which caninclude a network access layer designed for low-power IoT applicationsutilizing short-lived UE connections. An IoT UE can utilize technologiessuch as M2M or MTC for exchanging data with an MTC server or deviceusing, for example, a public land mobile network (PLMN), proximityservices (ProSe), device-to-device (D2D) communication, sensor networks,IoT networks, or combinations of them, among others. The M2M or MTCexchange of data may be a machine-initiated exchange of data. An IoTnetwork describes interconnecting IoT UEs, which can include uniquelyidentifiable embedded computing devices (within the Internetinfrastructure), with short-lived connections. The IoT UEs may executebackground applications (e.g., keep-alive messages or status updates) tofacilitate the connections of the IoT network.

The UEs 101 are configured to connect (e.g., communicatively couple)with a radio access network (RAN) 110. In some implementations, the RAN110 may be a next generation RAN (NG RAN), an evolved UMTS terrestrialradio access network (E-UTRAN), or a legacy RAN, such as a UMTSterrestrial radio access network (UTRAN) or a GSM EDGE radio accessnetwork (GERAN). As used herein, the term “NG RAN” may refer to a RAN110 that operates in a 5G NR system 100, and the term “E-UTRAN” mayrefer to a RAN 110 that operates in an LTE or 4G system 100.

To connect to the RAN 110, the UEs 101 utilize connections (or channels)103 and 104, respectively, each of which can include a physicalcommunications interface or layer, as described below. In this example,the connections 103 and 104 are illustrated as an air interface toenable communicative coupling, and can be consistent with cellularcommunications protocols, such as a global system for mobilecommunications (GSM) protocol, a code-division multiple access (CDMA)network protocol, a push-to-talk (PTT) protocol, a PTT over cellular(POC) protocol, a universal mobile telecommunications system (UMTS)protocol, a 3GPP LTE protocol, a 5G NR protocol, or combinations ofthem, among other communication protocols.

The UE 101 b is shown to be configured to access an access point (AP)106 (also referred to as “WLAN node 106,” “WLAN 106,” “WLAN Termination106,” “WT 106” or the like) using a connection 107. The connection 107can include a local wireless connection, such as a connection consistentwith any IEEE 802.11 protocol, in which the AP 106 would include awireless fidelity (Wi-Fi) router. In this example, the AP 106 is shownto be connected to the Internet without connecting to the core networkof the wireless system, as described in further detail below.

The RAN 110 can include one or more nodes such as RAN nodes 111 a and111 b (collectively referred to as “RAN nodes 111” or “RAN node 111”)that enable the connections 103 and 104. As used herein, the terms“access node,” “access point,” or the like may describe equipment thatprovides the radio baseband functions for data or voice connectivity, orboth, between a network and one or more users. These access nodes can bereferred to as base stations (BS), gNodeBs, gNBs, eNodeBs, eNBs, NodeBs,RAN nodes, rode side units (RSUs), transmission reception points (TRxPsor TRPs), and the link, and can include ground stations (e.g.,terrestrial access points) or satellite stations providing coveragewithin a geographic area (e.g., a cell), among others. As used herein,the term “NG RAN node” may refer to a RAN node 111 that operates in an5G NR system 100 (for example, a gNB), and the term “E-UTRAN node” mayrefer to a RAN node 111 that operates in an LTE or 4G system 100 (e.g.,an eNB). In some implementations, the RAN nodes 111 may be implementedas one or more of a dedicated physical device such as a macrocell basestation, or a low power (LP) base station for providing femtocells,picocells or other like cells having smaller coverage areas, smalleruser capacity, or higher bandwidth compared to macrocells.

In some implementations, some or all of the RAN nodes 111 may beimplemented as one or more software entities running on server computersas part of a virtual network, which may be referred to as a cloud RAN(CRAN) or a virtual baseband unit pool (vBBUP). The CRAN or vBBUP mayimplement a RAN function split, such as a packet data convergenceprotocol (PDCP) split in which radio resource control (RRC) and PDCPlayers are operated by the CRAN/vBBUP and other layer two (e.g., datalink layer) protocol entities are operated by individual RAN nodes 111;a medium access control (MAC)/physical layer (PHY) split in which RRC,PDCP, MAC, and radio link control (RLC) layers are operated by theCRAN/vBBUP and the PHY layer is operated by individual RAN nodes 111; ora “lower PHY” split in which RRC, PDCP, RLC, and MAC layers and upperportions of the PHY layer are operated by the CRAN/vBBUP and lowerportions of the PHY layer are operated by individual RAN nodes 111. Thisvirtualized framework allows the freed-up processor cores of the RANnodes 111 to perform, for example, other virtualized applications. Insome implementations, an individual RAN node 111 may representindividual gNB distributed units (DUs) that are connected to a gNBcentral unit (CU) using individual F1 interfaces (not shown in FIG. 1).In some implementations, the gNB-DUs can include one or more remoteradio heads or RFEMs (see, e.g., FIG. 4), and the gNB-CU may be operatedby a server that is located in the RAN 110 (not shown) or by a serverpool in a similar manner as the CRAN/vBBUP. Additionally oralternatively, one or more of the RAN nodes 111 may be next generationeNBs (ng-eNBs), including RAN nodes that provide E-UTRA user plane andcontrol plane protocol terminations toward the UEs 101, and areconnected to a 5G core network (e.g., core network 120) using a nextgeneration interface.

In vehicle-to-everything (V2X) scenarios, one or more of the RAN nodes111 may be or act as RSUs. The term “Road Side Unit” or “RSU” refers toany transportation infrastructure entity used for V2X communications. ARSU may be implemented in or by a suitable RAN node or a stationary (orrelatively stationary) UE, where a RSU implemented in or by a UE may bereferred to as a “UE-type RSU,” a RSU implemented in or by an eNB may bereferred to as an “eNB-type RSU,” a RSU implemented in or by a gNB maybe referred to as a “gNB-type RSU,” and the like. In someimplementations, an RSU is a computing device coupled with radiofrequency circuitry located on a roadside that provides connectivitysupport to passing vehicle UEs 101 (vUEs 101). The RSU may also includeinternal data storage circuitry to store intersection map geometry,traffic statistics, media, as well as applications or other software tosense and control ongoing vehicular and pedestrian traffic. The RSU mayoperate on the 5.9 GHz Direct Short Range Communications (DSRC) band toprovide very low latency communications required for high speed events,such as crash avoidance, traffic warnings, and the like. Additionally oralternatively, the RSU may operate on the cellular V2X band to providethe aforementioned low latency communications, as well as other cellularcommunications services. Additionally or alternatively, the RSU mayoperate as a Wi-Fi hotspot (2.4 GHz band) or provide connectivity to oneor more cellular networks to provide uplink and downlink communications,or both. The computing device(s) and some or all of the radiofrequencycircuitry of the RSU may be packaged in a weatherproof enclosuresuitable for outdoor installation, and can include a network interfacecontroller to provide a wired connection (e.g., Ethernet) to a trafficsignal controller or a backhaul network, or both.

Any of the RAN nodes 111 can terminate the air interface protocol andcan be the first point of contact for the UEs 101. In someimplementations, any of the RAN nodes 111 can fulfill various logicalfunctions for the RAN 110 including, but not limited to, radio networkcontroller (RNC) functions such as radio bearer management, uplink anddownlink dynamic radio resource management and data packet scheduling,and mobility management.

In some implementations, the UEs 101 can be configured to communicateusing orthogonal frequency division multiplexing (OFDM) communicationsignals with each other or with any of the RAN nodes 111 over amulticarrier communication channel in accordance with variouscommunication techniques, such as, but not limited to, OFDMAcommunication techniques (e.g., for downlink communications) or SC-FDMAcommunication techniques (e.g., for uplink communications), although thescope of the techniques described here not limited in this respect. TheOFDM signals can comprise a plurality of orthogonal subcarriers.

The RAN nodes 111 can transmit to the UEs 101 over various channels.Various examples of downlink communication channels include PhysicalBroadcast Channel (PBCH), Physical Downlink Control Channel (PDCCH), andPhysical Downlink Shared Channel (PDSCH). Other types of downlinkchannels are possible. The UEs 101 can transmit to the RAN nodes 111over various channels. Various examples of uplink communication channelsinclude Physical Uplink Shared Channel (PUSCH), Physical Uplink ControlChannel (PUCCH), and Physical Random Access Channel (PRACH). Other typesof uplink channels are possible.

In some implementations, a downlink resource grid can be used fordownlink transmissions from any of the RAN nodes 111 to the UEs 101,while uplink transmissions can utilize similar techniques. The grid canbe a time-frequency grid, called a resource grid or time-frequencyresource grid, which is the physical resource in the downlink in eachslot. Such a time-frequency plane representation is a common practicefor OFDM systems, which makes it intuitive for radio resourceallocation. Each column and each row of the resource grid corresponds toone OFDM symbol and one OFDM subcarrier, respectively. The duration ofthe resource grid in the time domain corresponds to one slot in a radioframe. The smallest time-frequency unit in a resource grid is denoted asa resource element. Each resource grid comprises a number of resourceblocks, which describe the mapping of certain physical channels toresource elements. Each resource block comprises a collection ofresource elements; in the frequency domain, this may represent thesmallest quantity of resources that currently can be allocated. Thereare several different physical downlink channels that are conveyed usingsuch resource blocks.

The PDSCH carries user data and higher-layer signaling to the UEs 101.The PDCCH carries information about the transport format and resourceallocations related to the PDSCH channel, among other things. It mayalso inform the UEs 101 about the transport format, resource allocation,and hybrid automatic repeat request (HARQ) information related to theuplink shared channel. Downlink scheduling (e.g., assigning control andshared channel resource blocks to the UE 101 b within a cell) may beperformed at any of the RAN nodes 111 based on channel qualityinformation fed back from any of the UEs 101. The downlink resourceassignment information may be sent on the PDCCH used for (e.g., assignedto) each of the UEs 101.

The PDCCH uses control channel elements (CCEs) to convey the controlinformation. Before being mapped to resource elements, the PDCCHcomplex-valued symbols may first be organized into quadruplets, whichmay then be permuted using a sub-block interleaver for rate matching. Insome implementations, each PDCCH may be transmitted using one or more ofthese CCEs, in which each CCE may correspond to nine sets of fourphysical resource elements collectively referred to as resource elementgroups (REGs). Four Quadrature Phase Shift Keying (QPSK) symbols may bemapped to each REG. The PDCCH can be transmitted using one or more CCEs,depending on the size of the downlink control information (DCI) and thechannel condition. In LTE, there can be four or more different PDCCHformats defined with different numbers of CCEs (e.g., aggregation level,L=1, 2, 4, or 8).

Some implementations may use concepts for resource allocation forcontrol channel information that are an extension of the above-describedconcepts. For example, some implementations may utilize an enhancedPDCCH (EPDCCH) that uses PDSCH resources for control informationtransmission. The EPDCCH may be transmitted using one or more enhancedCCEs (ECCEs). Similar to above, each ECCE may correspond to nine sets offour physical resource elements collectively referred to as an enhancedREG (EREG). An ECCE may have other numbers of EREGs.

The RAN nodes 111 are configured to communicate with one another usingan interface 112. In examples, such as where the system 100 is an LTEsystem (e.g., when the core network 120 is an evolved packet core (EPC)network as shown in FIG. 2), the interface 112 may be an X2 interface112. The X2 interface may be defined between two or more RAN nodes 111(e.g., two or more eNBs and the like) that connect to the EPC 120, orbetween two eNBs connecting to EPC 120, or both. In someimplementations, the X2 interface can include an X2 user plane interface(X2-U) and an X2 control plane interface (X2-C). The X2-U may provideflow control mechanisms for user data packets transferred over the X2interface, and may be used to communicate information about the deliveryof user data between eNBs. For example, the X2-U may provide specificsequence number information for user data transferred from a master eNBto a secondary eNB; information about successful in sequence delivery ofPDCP protocol data units (PDUs) to a UE 101 from a secondary eNB foruser data; information of PDCP PDUs that were not delivered to a UE 101;information about a current minimum desired buffer size at the secondaryeNB for transmitting to the UE user data, among other information. TheX2-C may provide intra-LTE access mobility functionality, includingcontext transfers from source to target eNBs or user plane transportcontrol; load management functionality; inter-cell interferencecoordination functionality, among other functionality.

In some implementations, such as where the system 100 is a 5G NR system(e.g., when the core network 120 is a 5G core network as shown in FIG.3), the interface 112 may be an Xn interface 112. The Xn interface maybe defined between two or more RAN nodes 111 (e.g., two or more gNBs andthe like) that connect to the 5G core network 120, between a RAN node111 (e.g., a gNB) connecting to the 5G core network 120 and an eNB, orbetween two eNBs connecting to the 5G core network 120, or combinationsof them. In some implementations, the Xn interface can include an Xnuser plane (Xn-U) interface and an Xn control plane (Xn-C) interface.The Xn-U may provide non-guaranteed delivery of user plane PDUs andsupport/provide data forwarding and flow control functionality. The Xn-Cmay provide management and error handling functionality, functionalityto manage the Xn-C interface; mobility support for UE 101 in a connectedmode (e.g., CM-CONNECTED) including functionality to manage the UEmobility for connected mode between one or more RAN nodes 111, amongother functionality. The mobility support can include context transferfrom an old (source) serving RAN node 111 to new (target) serving RANnode 111, and control of user plane tunnels between old (source) servingRAN node 111 to new (target) serving RAN node 111. A protocol stack ofthe Xn-U can include a transport network layer built on InternetProtocol (IP) transport layer, and a GPRS tunneling protocol for userplane (GTP-U) layer on top of a user datagram protocol (UDP) or IPlayer(s), or both, to carry user plane PDUs. The Xn-C protocol stack caninclude an application layer signaling protocol (referred to as XnApplication Protocol (Xn-AP or XnAP)) and a transport network layer(TNL) that is built on a stream control transmission protocol (SCTP).The SCTP may be on top of an IP layer, and may provide the guaranteeddelivery of application layer messages. In the transport IP layer,point-to-point transmission is used to deliver the signaling PDUs. Inother implementations, the Xn-U protocol stack or the Xn-C protocolstack, or both, may be same or similar to the user plane and/or controlplane protocol stack(s) shown and described herein.

The RAN 110 is shown to be communicatively coupled to a core network 120(referred to as a “CN 120”). The CN 120 includes one or more networkelements 122, which are configured to offer various data andtelecommunications services to customers/subscribers (e.g., users of UEs101) who are connected to the CN 120 using the RAN 110. The componentsof the CN 120 may be implemented in one physical node or separatephysical nodes and can include components to read and executeinstructions from a machine-readable or computer-readable medium (e.g.,a non-transitory machine-readable storage medium). In someimplementations, network functions virtualization (NFV) may be used tovirtualize some or all of the network node functions described hereusing executable instructions stored in one or more computer-readablestorage mediums, as described in further detail below. A logicalinstantiation of the CN 120 may be referred to as a network slice, and alogical instantiation of a portion of the CN 120 may be referred to as anetwork sub-slice. NFV architectures and infrastructures may be used tovirtualize one or more network functions, alternatively performed byproprietary hardware, onto physical resources comprising a combinationof industry-standard server hardware, storage hardware, or switches. Inother words, NFV systems can be used to execute virtual orreconfigurable implementations of one or more network components orfunctions, or both.

An application server 130 may be an element offering applications thatuse IP bearer resources with the core network (e.g., UMTS packetservices (PS) domain, LTE PS data services, among others). Theapplication server 130 can also be configured to support one or morecommunication services (e.g., VoIP sessions, PTT sessions, groupcommunication sessions, social networking services, among others) forthe UEs 101 using the CN 120. The application server 130 can use an IPcommunications interface 125 to communicate with one or more networkelements 112.

In some implementations, the CN 120 may be a 5G core network (referredto as “5GC 120” or “5G core network 120”), and the RAN 110 may beconnected with the CN 120 using a next generation interface 113. In someimplementations, the next generation interface 113 may be split into twoparts, an next generation user plane (NG-U) interface 114, which carriestraffic data between the RAN nodes 111 and a user plane function (UPF),and the S1 control plane (NG-C) interface 115, which is a signalinginterface between the RAN nodes 111 and access and mobility managementfunctions (AMFs). Examples where the CN 120 is a 5G core network arediscussed in more detail with regard to FIG. 3.

In some implementations, the CN 120 may be an EPC (referred to as “EPC120” or the like), and the RAN 110 may be connected with the CN 120using an S1 interface 113. In some implementations, the S1 interface 113may be split into two parts, an S1 user plane (S1-U) interface 114,which carries traffic data between the RAN nodes 111 and the servinggateway (S-GW), and the S1-MME interface 115, which is a signalinginterface between the RAN nodes 111 and mobility management entities(MMEs).

FIG. 2 illustrates an example architecture of a system 200 including afirst CN 220. In this example, the system 200 may implement the LTEstandard such that the CN 220 is an EPC 220 that corresponds with CN 120of FIG. 1. Additionally, the UE 201 may be the same or similar as theUEs 101 of FIG. 1, and the E-UTRAN 210 may be a RAN that is the same orsimilar to the RAN 110 of FIG. 1, and which can include RAN nodes 111discussed previously. The CN 220 may comprise MMEs 221, an S-GW 222, aPDN gateway (P-GW) 223, a high-speed packet access (HSS) function 224,and a serving GPRS support node (SGSN) 225.

The MMEs 221 may be similar in function to the control plane of legacySGSN, and may implement mobility management (MM) functions to keep trackof the current location of a UE 201. The MMEs 221 may perform variousmobility management procedures to manage mobility aspects in access suchas gateway selection and tracking area list management. Mobilitymanagement (also referred to as “EPS MM” or “EMM” in E-UTRAN systems)may refer to all applicable procedures, methods, data storage, and otheraspects that are used to maintain knowledge about a present location ofthe UE 201, provide user identity confidentiality, or perform other likeservices to users/subscribers, or combinations of them, among others.Each UE 201 and the MME 221 can include an EMM sublayer, and an mobilitymanagement context may be established in the UE 201 and the MME 221 whenan attach procedure is successfully completed. The mobility managementcontext may be a data structure or database object that stores mobilitymanagement-related information of the UE 201. The MMEs 221 may becoupled with the HSS 224 using a S6a reference point, coupled with theSGSN 225 using a S3 reference point, and coupled with the S-GW 222 usinga S11 reference point.

The SGSN 225 may be a node that serves the UE 201 by tracking thelocation of an individual UE 201 and performing security functions. Inaddition, the SGSN 225 may perform Inter-EPC node signaling for mobilitybetween 2G/3G and E-UTRAN 3GPP access networks; PDN and S-GW selectionas specified by the MMEs 221; handling of UE 201 time zone functions asspecified by the MMEs 221; and MME selection for handovers to E-UTRAN3GPP access network, among other functions. The S3 reference pointbetween the MMEs 221 and the SGSN 225 may enable user and bearerinformation exchange for inter-3GPP access network mobility in idle oractive states, or both.

The HSS 224 can include a database for network users, includingsubscription-related information to support the network entities'handling of communication sessions. The EPC 220 can include one or moreHSSs 224 depending on the number of mobile subscribers, on the capacityof the equipment, on the organization of the network, or combinations ofthem, among other features. For example, the HSS 224 can provide supportfor routing, roaming, authentication, authorization, naming/addressingresolution, location dependencies, among others. A S6a reference pointbetween the HSS 224 and the MMEs 221 may enable transfer of subscriptionand authentication data for authenticating or authorizing user access tothe EPC 220 between HSS 224 and the MMEs 221.

The S-GW 222 may terminate the S1 interface 113 (“S1-U” in FIG. 2)toward the RAN 210, and may route data packets between the RAN 210 andthe EPC 220. In addition, the S-GW 222 may be a local mobility anchorpoint for inter-RAN node handovers and also may provide an anchor forinter-3GPP mobility. Other responsibilities can include lawfulintercept, charging, and some policy enforcement. The S11 referencepoint between the S-GW 222 and the MMEs 221 may provide a control planebetween the MMEs 221 and the S-GW 222. The S-GW 222 may be coupled withthe P-GW 223 using a S5 reference point.

The P-GW 223 may terminate a SGi interface toward a PDN 230. The P-GW223 may route data packets between the EPC 220 and external networkssuch as a network including the application server 130 (sometimesreferred to as an “AF”) using an IP communications interface 125 (see,e.g., FIG. 1). In some implementations, the P-GW 223 may becommunicatively coupled to an application server (e.g., the applicationserver 130 of FIG. 1 or PDN 230 in FIG. 2) using an IP communicationsinterface 125 (see, e.g., FIG. 1). The S5 reference point between theP-GW 223 and the S-GW 222 may provide user plane tunneling and tunnelmanagement between the P-GW 223 and the S-GW 222. The S5 reference pointmay also be used for S-GW 222 relocation due to UE 201 mobility and ifthe S-GW 222 needs to connect to a non-collocated P-GW 223 for therequired PDN connectivity. The P-GW 223 may further include a node forpolicy enforcement and charging data collection (e.g., PCEF (notshown)). Additionally, the SGi reference point between the P-GW 223 andthe packet data network (PDN) 230 may be an operator external public, aprivate PDN, or an intra operator packet data network, for example, forprovision of IMS services. The P-GW 223 may be coupled with a policycontrol and charging rules function (PCRF) 226 using a Gx referencepoint.

PCRF 226 is the policy and charging control element of the EPC 220. In anon-roaming scenario, there may be a single PCRF 226 in the Home PublicLand Mobile Network (HPLMN) associated with a UE 201's Internet ProtocolConnectivity Access Network (IP-CAN) session. In a roaming scenario withlocal breakout of traffic, there may be two PCRFs associated with a UE201's IP-CAN session, a Home PCRF (H-PCRF) within an HPLMN and a VisitedPCRF (V-PCRF) within a Visited Public Land Mobile Network (VPLMN). ThePCRF 226 may be communicatively coupled to the application server 230using the P-GW 223. The application server 230 may signal the PCRF 226to indicate a new service flow and select the appropriate quality ofservice (QoS) and charging parameters. The PCRF 226 may provision thisrule into a PCEF (not shown) with the appropriate traffic flow template(TFT) and QoS class identifier (QCI), which commences the QoS andcharging as specified by the application server 230. The Gx referencepoint between the PCRF 226 and the P-GW 223 may allow for the transferof QoS policy and charging rules from the PCRF 226 to PCEF in the P-GW223. A Rx reference point may reside between the PDN 230 (or “AF 230”)and the PCRF 226.

FIG. 3 illustrates an architecture of a system 300 including a second CN320. The system 300 is shown to include a UE 301, which may be the sameor similar to the UEs 101 and UE 201 discussed previously; a RAN 310,which may be the same or similar to the RAN 110 and RAN 210 discussedpreviously, and which can include RAN nodes 111 discussed previously;and a data network (DN) 303, which may be, for example, operatorservices, Internet access or 3rd party services; and a 5GC 320. The 5GC320 can include an authentication server function (AUSF) 322; an accessand mobility management function (AMF) 321; a session managementfunction (SMF) 324; a network exposure function (NEF) 323; a policycontrol function (PCF) 326; a network repository function (NRF) 325; aunified data management (UDM) function 327; an AF 328; a user planefunction (UPF) 302; and a network slice selection function (NSSF) 329.

The UPF 302 may act as an anchor point for intra-RAT and inter-RATmobility, an external PDU session point of interconnect to DN 303, and abranching point to support multi-homed PDU session. The UPF 302 may alsoperform packet routing and forwarding, perform packet inspection,enforce the user plane part of policy rules, lawfully intercept packets(UP collection), perform traffic usage reporting, perform QoS handlingfor a user plane (e.g., packet filtering, gating, UL/DL rateenforcement), perform Uplink Traffic verification (e.g., SDF to QoS flowmapping), transport level packet marking in the uplink and downlink, andperform downlink packet buffering and downlink data notificationtriggering. UPF 302 can include an uplink classifier to support routingtraffic flows to a data network. The DN 303 may represent variousnetwork operator services, Internet access, or third party services. DN303 can include, or be similar to, application server 130 discussedpreviously. The UPF 302 may interact with the SMF 324 using a N4reference point between the SMF 324 and the UPF 302.

The AUSF 322 stores data for authentication of UE 301 and handleauthentication-related functionality. The AUSF 322 may facilitate acommon authentication framework for various access types. The AUSF 322may communicate with the AMF 321 using a N12 reference point between theAMF 321 and the AUSF 322, and may communicate with the UDM 327 using aN13 reference point between the UDM 327 and the AUSF 322. Additionally,the AUSF 322 may exhibit a Nausf service-based interface.

The AMF 321 is responsible for registration management (e.g., forregistering UE 301), connection management, reachability management,mobility management, and lawful interception of AMF-related events, andaccess authentication and authorization. The AMF 321 may be atermination point for the N11 reference point between the AMF 321 andthe SMF 324. The AMF 321 may provide transport for SM messages betweenthe UE 301 and the SMF 324, and act as a transparent pro10 for routingSM messages. AMF 321 may also provide transport for SMS messages betweenUE 301 and an SMSF (not shown in FIG. 3). AMF 321 may act as securityanchor function (SEAF), which can include interaction with the AUSF 322and the UE 301 to, for example, receive an intermediate key that wasestablished as a result of the UE 301 authentication process. Whereuniversal subscriber identity module (USIM) based authentication isused, the AMF 321 may retrieve the security material from the AUSF 322.AMF 321 may also include a security context management (SCM) function,which receives a key from the SEAF to derive access-network specifickeys. Furthermore, AMF 321 may be a termination point of a RAN controlplane interface, which can include or be a N2 reference point betweenthe RAN 310 and the AMF 321. In some implementations, the AMF 321 may bea termination point of NAS (N1) signaling and perform NAS ciphering andintegrity protection.

AMF 321 may also support NAS signaling with a UE 301 over a N3interworking function (IWF) interface (referred to as the “N3IWF”). TheN3IWF may be used to provide access to untrusted entities. The N3IWF maybe a termination point for the N2 interface between the RAN 310 and theAMF 321 for the control plane, and may be a termination point for the N3reference point between the RAN 310 and the UPF 302 for the user plane.As such, the AMF 321 may handle N2 signaling from the SMF 324 and theAMF 321 for PDU sessions and QoS, encapsulate/de-encapsulate packets forIPsec and N3 tunneling, mark N3 user-plane packets in the uplink, andenforce QoS corresponding to N3 packet marking taking into account QoSrequirements associated with such marking received over N2. The N3IWFmay also relay uplink and downlink control-plane NAS signaling betweenthe UE 301 and AMF 321 using a N1 reference point between the UE 301 andthe AMF 321, and relay uplink and downlink user-plane packets betweenthe UE 301 and UPF 302. The N3IWF also provides mechanisms for IPsectunnel establishment with the UE 301. The AMF 321 may exhibit a Namfservice-based interface, and may be a termination point for a N14reference point between two AMFs 321 and a N17 reference point betweenthe AMF 321 and a 5G equipment identity registry (EIR) (not shown inFIG. 3).

The UE 301 may register with the AMF 321 in order to receive networkservices. Registration management (RM) is used to register or deregisterthe UE 301 with the network (e.g., AMF 321), and establish a UE contextin the network (e.g., AMF 321). The UE 301 may operate in aRM-REGISTERED state or an RM-DEREGISTERED state. In the RM DEREGISTEREDstate, the UE 301 is not registered with the network, and the UE contextin AMF 321 holds no valid location or routing information for the UE 301so the UE 301 is not reachable by the AMF 321. In the RM REGISTEREDstate, the UE 301 is registered with the network, and the UE context inAMF 321 may hold a valid location or routing information for the UE 301so the UE 301 is reachable by the AMF 321. In the RM-REGISTERED state,the UE 301 may perform mobility Registration Update procedures, performperiodic Registration Update procedures triggered by expiration of theperiodic update timer (e.g., to notify the network that the UE 301 isstill active), and perform a Registration Update procedure to update UEcapability information or to re-negotiate protocol parameters with thenetwork, among others.

The AMF 321 may store one or more RM contexts for the UE 301, where eachRM context is associated with a specific access to the network. The RMcontext may be, for example, a data structure or database object, amongothers, that indicates or stores a registration state per access typeand the periodic update timer. The AMF 321 may also store a 5GC mobilitymanagement (MM) context that may be the same or similar to the (E)MMcontext discussed previously. In some implementations, the AMF 321 maystore a coverage enhancement mode B Restriction parameter of the UE 301in an associated MM context or RM context. The AMF 321 may also derivethe value, when needed, from the UE's usage setting parameter alreadystored in the UE context (and/or MM/RM context).

Connection management (CM) may be used to establish and release asignaling connection between the UE 301 and the AMF 321 over the N1interface. The signaling connection is used to enable NAS signalingexchange between the UE 301 and the CN 320, and includes both thesignaling connection between the UE and the RAN (e.g., RRC connection orUE-N3IWF connection for non-3GPP access) and the N2 connection for theUE 301 between the AN (e.g., RAN 310) and the AMF 321. In someimplementations, the UE 301 may operate in one of two CM modes: CM-IDLEmode or CM-CONNECTED mode. When the UE 301 is operating in the CM-IDLEmode, the UE 301 may have no NAS signaling connection established withthe AMF 321 over the N1 interface, and there may be RAN 310 signalingconnection (e.g., N2 or N3 connections, or both) for the UE 301. Whenthe UE 301 is operating in the CM-CONNECTED mode, the UE 301 may have anestablished NAS signaling connection with the AMF 321 over the N1interface, and there may be a RAN 310 signaling connection (e.g., N2and/or N3 connections) for the UE 301. Establishment of a N2 connectionbetween the RAN 310 and the AMF 321 may cause the UE 301 to transitionfrom the CM-IDLE mode to the CM-CONNECTED mode, and the UE 301 maytransition from the CM-CONNECTED mode to the CM-IDLE mode when N2signaling between the RAN 310 and the AMF 321 is released.

The SMF 324 may be responsible for session management (SM), such assession establishment, modify and release, including tunnel maintainbetween UPF and AN node; UE IP address allocation and management(including optional authorization); selection and control of UPfunction; configuring traffic steering at the UPF to route traffic toproper destination; termination of interfaces toward policy controlfunctions; controlling part of policy enforcement and QoS; lawfulintercept (for SM events and interface to LI system); termination of SMparts of NAS messages; downlink data notification; initiating ANspecific SM information, sent using AMF over N2 to AN; and determiningSSC mode of a session. SM may refer to management of a PDU session, anda PDU session (or “session”) may refer to a PDU connectivity servicethat provides or enables the exchange of PDUs between a UE 301 and adata network (DN) 303 identified by a Data Network Name (DNN). PDUsessions may be established upon UE 301 request, modified upon UE 301and 5GC 320 request, and released upon UE 301 and 5GC 320 request usingNAS SM signaling exchanged over the N1 reference point between the UE301 and the SMF 324. Upon request from an application server, the 5GC320 may trigger a specific application in the UE 301. In response toreceipt of the trigger message, the UE 301 may pass the trigger message(or relevant parts/information of the trigger message) to one or moreidentified applications in the UE 301. The identified application(s) inthe UE 301 may establish a PDU session to a specific DNN. The SMF 324may check whether the UE 301 requests are compliant with usersubscription information associated with the UE 301. In this regard, theSMF 324 may retrieve and/or request to receive update notifications onSMF 324 level subscription data from the UDM 327.

The SMF 324 can include some or all of the following roamingfunctionality: handling local enforcement to apply QoS service levelagreements (SLAs) (e.g., in VPLMN); charging data collection andcharging interface (e.g., in VPLMN); lawful intercept (e.g., in VPLMNfor SM events and interface to LI system); and support for interactionwith external DN for transport of signaling for PDU sessionauthorization/authentication by external DN. A N16 reference pointbetween two SMFs 324 may be included in the system 300, which may bebetween another SMF 324 in a visited network and the SMF 324 in the homenetwork in roaming scenarios. Additionally, the SMF 324 may exhibit theNsmf service-based interface.

The NEF 323 may provide means for securely exposing the services andcapabilities provided by 3GPP network functions for third party,internal exposure/re-exposure, Application Functions (e.g., AF 328),edge computing or fog computing systems, among others. In someimplementations, the NEF 323 may authenticate, authorize, and/orthrottle the AFs. The NEF 323 may also translate information exchangedwith the AF 328 and information exchanged with internal networkfunctions. For example, the NEF 323 may translate between anAF-Service-Identifier and an internal 5GC information. NEF 323 may alsoreceive information from other network functions (NFs) based on exposedcapabilities of other network functions. This information may be storedat the NEF 323 as structured data, or at a data storage NF usingstandardized interfaces. The stored information can then be re-exposedby the NEF 323 to other NFs and AFs, or used for other purposes such asanalytics, or both. Additionally, the NEF 323 may exhibit a Nnefservice-based interface.

The NRF 325 may support service discovery functions, receive NFdiscovery requests from NF instances, and provide the information of thediscovered NF instances to the NF instances. NRF 325 also maintainsinformation of available NF instances and their supported services. Asused herein, the terms “instantiate,” “instantiation,” and the like mayrefer to the creation of an instance, and an “instance” may refer to aconcrete occurrence of an object, which may occur, for example, duringexecution of program code. Additionally, the NRF 325 may exhibit theNnrf service-based interface.

The PCF 326 may provide policy rules to control plane function(s) toenforce them, and may also support unified policy framework to governnetwork behavior. The PCF 326 may also implement a front end to accesssubscription information relevant for policy decisions in a unified datarepository (UDR) of the UDM 327. The PCF 326 may communicate with theAMF 321 using an N15 reference point between the PCF 326 and the AMF321, which can include a PCF 326 in a visited network and the AMF 321 incase of roaming scenarios. The PCF 326 may communicate with the AF 328using a N5 reference point between the PCF 326 and the AF 328; and withthe SMF 324 using a N7 reference point between the PCF 326 and the SMF324. The system 300 or CN 320, or both, may also include a N24 referencepoint between the PCF 326 (in the home network) and a PCF 326 in avisited network. Additionally, the PCF 326 may exhibit a Npcfservice-based interface.

The UDM 327 may handle subscription-related information to support thenetwork entities' handling of communication sessions, and may storesubscription data of UE 301. For example, subscription data may becommunicated between the UDM 327 and the AMF 321 using a N8 referencepoint between the UDM 327 and the AMF. The UDM 327 can include twoparts, an application front end and a UDR (the front end and UDR are notshown in FIG. 3). The UDR may store subscription data and policy datafor the UDM 327 and the PCF 326, or structured data for exposure andapplication data (including PFDs for application detection, applicationrequest information for multiple UEs 301) for the NEF 323, or both. TheNudr service-based interface may be exhibited by the UDR 221 to allowthe UDM 327, PCF 326, and NEF 323 to access a particular set of thestored data, as well as to read, update (e.g., add, modify), delete, andsubscribe to notification of relevant data changes in the UDR. The UDMcan include a UDM front end, which is in charge of processingcredentials, location management, subscription management and so on.Several different front ends may serve the same user in differenttransactions. The UDM front end accesses subscription information storedin the UDR and performs authentication credential processing, useridentification handling, access authorization, registration/mobilitymanagement, and subscription management. The UDR may interact with theSMF 324 using a N10 reference point between the UDM 327 and the SMF 324.UDM 327 may also support SMS management, in which an SMS front endimplements the similar application logic as discussed previously.Additionally, the UDM 327 may exhibit the Nudm service-based interface.

The AF 328 may provide application influence on traffic routing, provideaccess to the network capability exposure (NCE), and interact with thepolicy framework for policy control. The NCE may be a mechanism thatallows the 5GC 320 and AF 328 to provide information to each other usingNEF 323, which may be used for edge computing implementations. In suchimplementations, the network operator and third party services may behosted close to the UE 301 access point of attachment to achieve anefficient service delivery through the reduced end-to-end latency andload on the transport network. For edge computing implementations, the5GC may select a UPF 302 close to the UE 301 and execute trafficsteering from the UPF 302 to DN 303 using the N6 interface. This may bebased on the UE subscription data, UE location, and information providedby the AF 328. In this way, the AF 328 may influence UPF (re)selectionand traffic routing. Based on operator deployment, when AF 328 isconsidered to be a trusted entity, the network operator may permit AF328 to interact directly with relevant NFs. Additionally, the AF 328 mayexhibit a Naf service-based interface.

The NSSF 329 may select a set of network slice instances serving the UE301. The NSSF 329 may also determine allowed NSSAI and the mapping tothe subscribed single network slice selection assistance information(S-NSSAI), if needed. The NSSF 329 may also determine the AMF set to beused to serve the UE 301, or a list of candidate AMF(s) 321 based on asuitable configuration and possibly by querying the NRF 325. Theselection of a set of network slice instances for the UE 301 may betriggered by the AMF 321 with which the UE 301 is registered byinteracting with the NSSF 329, which may lead to a change of AMF 321.The NSSF 329 may interact with the AMF 321 using an N22 reference pointbetween AMF 321 and NSSF 329; and may communicate with another NSSF 329in a visited network using a N31 reference point (not shown by FIG. 3).Additionally, the NSSF 329 may exhibit a Nnssf service-based interface.

As discussed previously, the CN 320 can include an SMSF, which may beresponsible for SMS subscription checking and verification, and relayingSM messages to or from the UE 301 to or from other entities, such as anSMS-GMSC/IWMSC/SMS-router. The SMS may also interact with AMF 321 andUDM 327 for a notification procedure that the UE 301 is available forSMS transfer (e.g., set a UE not reachable flag, and notifying UDM 327when UE 301 is available for SMS).

The CN 120 may also include other elements that are not shown in FIG. 3,such as a data storage system, a 5G-EIR, a security edge protectionpro10 (SEPP), and the like. The data storage system can include astructured data storage function (SDSF), an unstructured data storagefunction (UDSF), or both, among others. Any network function may storeand retrieve unstructured data to or from the UDSF (e.g., UE contexts),using a N18 reference point between any NF and the UDSF (not shown inFIG. 3). Individual network functions may share a UDSF for storing theirrespective unstructured data or individual network functions may eachhave their own UDSF located at or near the individual network functions.Additionally, the UDSF may exhibit a Nudsf service-based interface (notshown in FIG. 3). The 5G-EIR may be a network function that checks thestatus of permanent equipment identifiers (PEI) for determining whetherparticular equipment or entities are blacklisted from the network; andthe SEPP may be a non-transparent pro10 that performs topology hiding,message filtering, and policing on inter-PLMN control plane interfaces.

In some implementations, there may be additional or alternativereference points or service-based interfaces, or both, between thenetwork function services in the network functions. However, theseinterfaces and reference points have been omitted from FIG. 3 forclarity. In one example, the CN 320 can include a Nx interface, which isan inter-CN interface between the MME (e.g., MME 221) and the AMF 321 inorder to enable interworking between CN 320 and CN 220. Other exampleinterfaces or reference points can include a N5g-EIR service-basedinterface exhibited by a 5G-EIR, a N27 reference point between the NRFin the visited network and the NRF in the home network, or a N31reference point between the NSSF in the visited network and the NSSF inthe home network, among others.

In some implementations, the components of the CN 220 may be implementedin one physical node or separate physical nodes and can includecomponents to read and execute instructions from a machine-readable orcomputer-readable medium (e.g., a non-transitory machine-readablestorage medium). In some implementations, the components of CN 320 maybe implemented in a same or similar manner as discussed herein withregard to the components of CN 220. In some implementations, NFV isutilized to virtualize any or all of the above-described network nodefunctions using executable instructions stored in one or morecomputer-readable storage mediums, as described in further detail below.A logical instantiation of the CN 220 may be referred to as a networkslice, and individual logical instantiations of the CN 220 may providespecific network capabilities and network characteristics. A logicalinstantiation of a portion of the CN 220 may be referred to as a networksub-slice, which can include the P-GW 223 and the PCRF 226.

As used herein, the terms “instantiate,” “instantiation,” and the likemay refer to the creation of an instance, and an “instance” may refer toa concrete occurrence of an object, which may occur, for example, duringexecution of program code. A network instance may refer to informationidentifying a domain, which may be used for traffic detection androuting in case of different IP domains or overlapping IP addresses. Anetwork slice instance may refer to a set of network functions (NFs)instances and the resources (e.g., compute, storage, and networkingresources) required to deploy the network slice.

With respect to 5G systems (see, e.g., FIG. 3), a network slice caninclude a RAN part and a CN part. The support of network slicing relieson the principle that traffic for different slices is handled bydifferent PDU sessions. The network can realize the different networkslices by scheduling or by providing different L1/L2 configurations, orboth. The UE 301 provides assistance information for network sliceselection in an appropriate RRC message if it has been provided by NAS.In some implementations, while the network can support large number ofslices, the UE need not support more than 8 slices simultaneously.

A network slice can include the CN 320 control plane and user plane NFs,NG-RANs 310 in a serving PLMN, and a N3IWF functions in the servingPLMN. Individual network slices may have different S-NSSAI or differentSSTs, or both. NSSAI includes one or more S-NSSAIs, and each networkslice is uniquely identified by an S-NSSAI. Network slices may differfor supported features and network functions optimizations. In someimplementations, multiple network slice instances may deliver the sameservices or features but for different groups of UEs 301 (e.g.,enterprise users). For example, individual network slices may deliverdifferent committed service(s) or may be dedicated to a particularcustomer or enterprise, or both. In this example, each network slice mayhave different S-NSSAIs with the same SST but with different slicedifferentiators. Additionally, a single UE may be served with one ormore network slice instances simultaneously using a 5G AN, and the UEmay be associated with eight different S-NSSAIs. Moreover, an AMF 321instance serving an individual UE 301 may belong to each of the networkslice instances serving that UE.

Network slicing in the NG-RAN 310 involves RAN slice awareness. RANslice awareness includes differentiated handling of traffic fordifferent network slices, which have been pre-configured. Sliceawareness in the NG-RAN 310 is introduced at the PDU session level byindicating the S-NSSAI corresponding to a PDU session in all signalingthat includes PDU session resource information. How the NG-RAN 310supports the slice enabling in terms of NG-RAN functions (e.g., the setof network functions that comprise each slice) is implementationdependent. The NG-RAN 310 selects the RAN part of the network sliceusing assistance information provided by the UE 301 or the 5GC 320,which unambiguously identifies one or more of the pre-configured networkslices in the PLMN. The NG-RAN 310 also supports resource management andpolicy enforcement between slices as per SLAs. A single NG-RAN node maysupport multiple slices, and the NG-RAN 310 may also apply anappropriate RRM policy for the SLA in place to each supported slice. TheNG-RAN 310 may also support QoS differentiation within a slice.

The NG-RAN 310 may also use the UE assistance information for theselection of an AMF 321 during an initial attach, if available. TheNG-RAN 310 uses the assistance information for routing the initial NASto an AMF 321. If the NG-RAN 310 is unable to select an AMF 321 usingthe assistance information, or the UE 301 does not provide any suchinformation, the NG-RAN 310 sends the NAS signaling to a default AMF321, which may be among a pool of AMFs 321. For subsequent accesses, theUE 301 provides a temp ID, which is assigned to the UE 301 by the 5GC320, to enable the NG-RAN 310 to route the NAS message to theappropriate AMF 321 as long as the temp ID is valid. The NG-RAN 310 isaware of, and can reach, the AMF 321 that is associated with the tempID. Otherwise, the method for initial attach applies.

The NG-RAN 310 supports resource isolation between slices. NG-RAN 310resource isolation may be achieved by means of RRM policies andprotection mechanisms that should avoid that shortage of sharedresources if one slice breaks the service level agreement for anotherslice. In some implementations, it is possible to fully dedicate NG-RAN310 resources to a certain slice. How NG-RAN 310 supports resourceisolation is implementation dependent.

Some slices may be available only in part of the network. Awareness inthe NG-RAN 310 of the slices supported in the cells of its neighbors maybe beneficial for inter-frequency mobility in connected mode. The sliceavailability may not change within the UE's registration area. TheNG-RAN 310 and the 5GC 320 are responsible to handle a service requestfor a slice that may or may not be available in a given area. Admissionor rejection of access to a slice may depend on factors such as supportfor the slice, availability of resources, support of the requestedservice by NG-RAN 310.

The UE 301 may be associated with multiple network slicessimultaneously. In case the UE 301 is associated with multiple slicessimultaneously, only one signaling connection is maintained, and forintra-frequency cell reselection, the UE 301 tries to camp on the bestcell. For inter-frequency cell reselection, dedicated priorities can beused to control the frequency on which the UE 301 camps. The 5GC 320 isto validate that the UE 301 has the rights to access a network slice.Prior to receiving an Initial Context Setup Request message, the NG-RAN310 may be allowed to apply some provisional or local policies based onawareness of a particular slice that the UE 301 is requesting to access.During the initial context setup, the NG-RAN 310 is informed of theslice for which resources are being requested.

FIG. 4 illustrates an example of infrastructure equipment 400. Theinfrastructure equipment 400 (or “system 400”) may be implemented as abase station, a radio head, a RAN node, such as the RAN nodes 111 or AP106 shown and described previously, an application server 130, or anyother component or device described herein. In other examples, thesystem 400 can be implemented in or by a UE.

The system 400 includes application circuitry 405, baseband circuitry410, one or more radio front end modules (RFEMs) 415, memory circuitry420, power management integrated circuitry (PMIC) 425, power teecircuitry 430, network controller circuitry 435, network interfaceconnector 440, satellite positioning circuitry 445, and user interfacecircuitry 450. In some implementations, the system 400 can includeadditional elements such as, for example, memory, storage, a display, acamera, one or more sensors, or an input/output (I/O) interface, orcombinations of them, among others. In other examples, the componentsdescribed with reference to the system 400 may be included in more thanone device. For example, the various circuitries may be separatelyincluded in more than one device for CRAN, vBBU, or otherimplementations.

The application circuitry 405 includes circuitry such as, but notlimited to, one or more processors (or processor cores), cache memory,one or more of low drop-out voltage regulators (LDOs), interruptcontrollers, serial interfaces such as SPI, I2C or universalprogrammable serial interface module, real time clock (RTC),timer-counters including interval and watchdog timers, general purposeinput/output (I/O or IO), memory card controllers such as Secure Digital(SD) MultiMediaCard (MMC) or similar, Universal Serial Bus (USB)interfaces, Mobile Industry Processor Interface (MIPI) interfaces andJoint Test Access Group (JTAG) test access ports. The processors (orcores) of the application circuitry 405 may be coupled with or caninclude memory or storage elements and may be configured to executeinstructions stored in the memory or storage to enable variousapplications or operating systems to run on the system 400. In someimplementations, the memory or storage elements can include on-chipmemory circuitry, which can include any suitable volatile ornon-volatile memory, such as DRAM, SRAM, EPROM, EEPROM, Flash memory,solid-state memory, or combinations of them, among other types ofmemory.

The processor(s) of the application circuitry 405 can include, forexample, one or more processor cores (CPUs), one or more applicationprocessors, one or more graphics processing units (GPUs), one or morereduced instruction set computing (RISC) processors, one or more AcornRISC Machine (ARM) processors, one or more complex instruction setcomputing (CISC) processors, one or more digital signal processors(DSP), one or more FPGAs, one or more PLDs, one or more ASICs, one ormore microprocessors or controllers, or combinations of them, amongothers. In some implementations, the application circuitry 405 caninclude, or may be, a special-purpose processor or controller configuredto carry out the various techniques described here. As examples, theprocessor(s) of application circuitry 405 can include one or more IntelPentium®, Core®, or Xeon® processor(s); Advanced Micro Devices (AMD)Ryzen® processor(s), Accelerated Processing Units (APUs), or Epyc®processors; ARM-based processor(s) licensed from ARM Holdings, Ltd. suchas the ARM Cortex-A family of processors and the ThunderX2® provided byCavium™, Inc.; a MIPS-based design from MIPS Technologies, Inc. such asMIPS Warrior P-class processors; and/or the like. In someimplementations, the system 400 may not utilize application circuitry405, and instead can include a special-purpose processor or controllerto process IP data received from an EPC or 5GC, for example.

In some implementations, the application circuitry 405 can include oneor more hardware accelerators, which may be microprocessors,programmable processing devices, or the like. The one or more hardwareaccelerators can include, for example, computer vision (CV) or deeplearning (DL) accelerators, or both. In some implementations, theprogrammable processing devices may be one or more a field-programmabledevices (FPDs) such as field-programmable gate arrays (FPGAs) and thelike; programmable logic devices (PLDs) such as complex PLDs (CPLDs) orhigh-capacity PLDs (HCPLDs); ASICs such as structured ASICs;programmable SoCs (PSoCs), or combinations of them, among others. Insuch implementations, the circuitry of application circuitry 405 caninclude logic blocks or logic fabric, and other interconnected resourcesthat may be programmed to perform various functions, such as theprocedures, methods, functions described herein. In someimplementations, the circuitry of application circuitry 405 can includememory cells (e.g., erasable programmable read-only memory (EPROM),electrically erasable programmable read-only memory (EEPROM), flashmemory, static memory (e.g., static random access memory (SRAM) oranti-fuses)) used to store logic blocks, logic fabric, data, or otherdata in look-up-tables (LUTs) and the like.

The baseband circuitry 410 may be implemented, for example, as asolder-down substrate including one or more integrated circuits, asingle packaged integrated circuit soldered to a main circuit board or amulti-chip module containing two or more integrated circuits.

The user interface circuitry 450 can include one or more user interfacesdesigned to enable user interaction with the system 400 or peripheralcomponent interfaces designed to enable peripheral component interactionwith the system 400. User interfaces can include, but are not limitedto, one or more physical or virtual buttons (e.g., a reset button), oneor more indicators (e.g., light emitting diodes (LEDs)), a physicalkeyboard or keypad, a mouse, a touchpad, a touchscreen, speakers orother audio emitting devices, microphones, a printer, a scanner, aheadset, a display screen or display device, or combinations of them,among others. Peripheral component interfaces can include, but are notlimited to, a nonvolatile memory port, a universal serial bus (USB)port, an audio jack, a power supply interface, among others.

The radio front end modules (RFEMs) 415 can include a millimeter wave(mmWave) RFEM and one or more sub-mmWave radio frequency integratedcircuits (RFICs). In some implementations, the one or more sub-mmWaveRFICs may be physically separated from the mmWave RFEM. The RFICs caninclude connections to one or more antennas or antenna arrays (see,e.g., antenna array 611 of FIG. 6), and the RFEM may be connected tomultiple antennas. In some implementations, both mmWave and sub-mmWaveradio functions may be implemented in the same physical RFEM 415, whichincorporates both mmWave antennas and sub-mmWave.

The memory circuitry 420 can include one or more of volatile memory,such as dynamic random access memory (DRAM) or synchronous dynamicrandom access memory (SDRAM), and nonvolatile memory (NVM), such ashigh-speed electrically erasable memory (commonly referred to as Flashmemory), phase change random access memory (PRAM), or magnetoresistiverandom access memory (MRAM), or combinations of them, among others. Insome implementations, the memory circuitry 420 can includethree-dimensional (3D) cross-point (XPOINT) memories from Intel® andMicron®. Memory circuitry 420 may be implemented as one or more ofsolder down packaged integrated circuits, socketed memory modules andplug-in memory cards, for example.

The PMIC 425 can include voltage regulators, surge protectors, poweralarm detection circuitry, and one or more backup power sources such asa battery or capacitor. The power alarm detection circuitry may detectone or more of brown out (under-voltage) and surge (over-voltage)conditions. The power tee circuitry 430 may provide for electrical powerdrawn from a network cable to provide both power supply and dataconnectivity to the infrastructure equipment 400 using a single cable.

The network controller circuitry 435 may provide connectivity to anetwork using a standard network interface protocol such as Ethernet,Ethernet over GRE Tunnels, Ethernet over Multiprotocol Label Switching(MPLS), or some other suitable protocol. Network connectivity may beprovided to and from the infrastructure equipment 400 using networkinterface connector 440 using a physical connection, which may beelectrical (commonly referred to as a “copper interconnect”), optical,or wireless. The network controller circuitry 435 can include one ormore dedicated processors or FPGAs, or both, to communicate using one ormore of the aforementioned protocols. In some implementations, thenetwork controller circuitry 435 can include multiple controllers toprovide connectivity to other networks using the same or differentprotocols.

The positioning circuitry 445 includes circuitry to receive and decodesignals transmitted or broadcasted by a positioning network of a globalnavigation satellite system (GNSS). Examples of a GNSS include UnitedStates' Global Positioning System (GPS), Russia's Global NavigationSystem (GLONASS), the European Union's Galileo system, China's BeiDouNavigation Satellite System, a regional navigation system or GNSSaugmentation system (e.g., Navigation with Indian Constellation (NAVIC),Japan's Quasi-Zenith Satellite System (QZSS), France's DopplerOrbitography and Radio-positioning Integrated by Satellite (DORIS)),among other systems. The positioning circuitry 445 can include varioushardware elements (e.g., including hardware devices such as switches,filters, amplifiers, antenna elements, and the like to facilitate OTAcommunications) to communicate with components of a positioning network,such as navigation satellite constellation nodes. In someimplementations, the positioning circuitry 445 can include aMicro-Technology for Positioning, Navigation, and Timing (Micro-PNT) ICthat uses a master timing clock to perform position tracking andestimation without GNSS assistance. The positioning circuitry 445 mayalso be part of, or interact with, the baseband circuitry 410 or RFEMs415, or both, to communicate with the nodes and components of thepositioning network. The positioning circuitry 445 may also provide data(e.g., position data, time data) to the application circuitry 405, whichmay use the data to synchronize operations with various infrastructure(e.g., RAN nodes 111).

The components shown by FIG. 4 may communicate with one another usinginterface circuitry, which can include any number of bus or interconnect(IX) technologies such as industry standard architecture (ISA), extendedISA (EISA), peripheral component interconnect (PCI), peripheralcomponent interconnect extended (PCIx), PCI express (PCIe), or anynumber of other technologies. The bus or IX may be a proprietary bus,for example, used in a SoC based system. Other bus or IX systems may beincluded, such as an I2C interface, an SPI interface, point to pointinterfaces, and a power bus, among others.

FIG. 5 illustrates an example of a platform 500 (or “device 500”). Insome implementations, the computer platform 500 may be suitable for useas UEs 101, 201, 301, application servers 130, or any other component ordevice discussed herein. The platform 500 can include any combinationsof the components shown in the example. The components of platform 500(or portions thereof) may be implemented as integrated circuits (ICs),discrete electronic devices, or other modules, logic, hardware,software, firmware, or a combination of them adapted in the computerplatform 500, or as components otherwise incorporated within a chassisof a larger system. The block diagram of FIG. 5 is intended to show ahigh level view of components of the platform 500. However, In someimplementations, the platform 500 can include fewer, additional, oralternative components, or a different arrangement of the componentsshown in FIG. 5.

The application circuitry 505 includes circuitry such as, but notlimited to, one or more processors (or processor cores), cache memory,and one or more of LDOs, interrupt controllers, serial interfaces suchas SPI, I2C or universal programmable serial interface module, RTC,timer-counters including interval and watchdog timers, general purposeI/O, memory card controllers such as SD MMC or similar, USB interfaces,MIPI interfaces, and JTAG test access ports. The processors (or cores)of the application circuitry 505 may be coupled with or can includememory/storage elements and may be configured to execute instructionsstored in the memory or storage to enable various applications oroperating systems to run on the system 500. In some implementations, thememory or storage elements may be on-chip memory circuitry, which caninclude any suitable volatile or non-volatile memory, such as DRAM,SRAM, EPROM, EEPROM, Flash memory, solid-state memory, or combinationsof them, among other types of memory.

The processor(s) of application circuitry 405 can include, for example,one or more processor cores, one or more application processors, one ormore GPUs, one or more RISC processors, one or more ARM processors, oneor more CISC processors, one or more DSP, one or more FPGAs, one or morePLDs, one or more ASICs, one or more microprocessors or controllers, amultithreaded processor, an ultra-low voltage processor, an embeddedprocessor, some other known processing element, or any suitablecombination thereof. In some implementations, the application circuitry405 can include, or may be, a special-purpose processor/controller tocarry out the techniques described herein.

As examples, the processor(s) of application circuitry 505 can includean Intel® Architecture Core™ based processor, such as a Quark™, anAtom™, an i3, an i5, an i7, or an MCU-class processor, or another suchprocessor available from Intel® Corporation, Santa Clara, Calif. Theprocessors of the application circuitry 505 may also be one or more ofAdvanced Micro Devices (AMD) Ryzen® processor(s) or AcceleratedProcessing Units (APUs); A5-A9 processor(s) from Apple® Inc.,Snapdragon™ processor(s) from Qualcomm® Technologies, Inc., TexasInstruments, Inc.® Open Multimedia Applications Platform (OMAP)™processor(s); a MIPS-based design from MIPS Technologies, Inc. such asMIPS Warrior M-class, Warrior I-class, and Warrior P-class processors;an ARM-based design licensed from ARM Holdings, Ltd., such as the ARMCortex-A, Cortex-R, and Cortex-M family of processors; or the like. Insome implementations, the application circuitry 505 may be a part of asystem on a chip (SoC) in which the application circuitry 505 and othercomponents are formed into a single integrated circuit, or a singlepackage, such as the Edison™ or Galileo™ SoC boards from Intel®Corporation.

Additionally or alternatively, the application circuitry 505 can includecircuitry such as, but not limited to, one or more a field-programmabledevices (FPDs) such as FPGAs; programmable logic devices (PLDs) such ascomplex PLDs (CPLDs), high-capacity PLDs (HCPLDs); ASICs such asstructured ASICs; programmable SoCs (PSoCs), or combinations of them,among others. In some implementations, the application circuitry 505 caninclude logic blocks or logic fabric, and other interconnected resourcesthat may be programmed to perform various functions, such as theprocedures, methods, functions described herein. In someimplementations, the application circuitry 505 can include memory cells(e.g., erasable programmable read-only memory (EPROM), electricallyerasable programmable read-only memory (EEPROM), flash memory, staticmemory (e.g., static random access memory (SRAM), or anti-fuses)) usedto store logic blocks, logic fabric, data, or other data in look-uptables (LUTs) and the like.

The baseband circuitry 510 may be implemented, for example, as asolder-down substrate including one or more integrated circuits, asingle packaged integrated circuit soldered to a main circuit board or amulti-chip module containing two or more integrated circuits. Thevarious hardware electronic elements of baseband circuitry 510 arediscussed with regard to FIG. 6.

The RFEMs 515 may comprise a millimeter wave (mmWave) RFEM and one ormore sub-mmWave radio frequency integrated circuits (RFICs). In someimplementations, the one or more sub-mmWave RFICs may be physicallyseparated from the mmWave RFEM. The RFICs can include connections to oneor more antennas or antenna arrays (see, e.g., antenna array 611 of FIG.6), and the RFEM may be connected to multiple antennas. In someimplementations, both mmWave and sub-mmWave radio functions may beimplemented in the same physical RFEM 515, which incorporates bothmmWave antennas and sub-mmWave.

The memory circuitry 520 can include any number and type of memorydevices used to provide for a given amount of system memory. Asexamples, the memory circuitry 520 can include one or more of volatilememory, such as random access memory (RAM), dynamic RAM (DRAM) orsynchronous dynamic RAM (SDRAM), and nonvolatile memory (NVM), such ashigh-speed electrically erasable memory (commonly referred to as Flashmemory), phase change random access memory (PRAM), or magnetoresistiverandom access memory (MRAM), or combinations of them, among others. Thememory circuitry 520 may be developed in accordance with a JointElectron Devices Engineering Council (JEDEC) low power double data rate(LPDDR)-based design, such as LPDDR2, LPDDR3, LPDDR4, or the like.Memory circuitry 520 may be implemented as one or more of solder downpackaged integrated circuits, single die package (SDP), dual die package(DDP) or quad die package (Q17P), socketed memory modules, dual inlinememory modules (DIMMs) including microDIMMs or MiniDIMMs, or solderedonto a motherboard using a ball grid array (BGA). In low powerimplementations, the memory circuitry 520 may be on-die memory orregisters associated with the application circuitry 505. To provide forpersistent storage of information such as data, applications, operatingsystems and so forth, memory circuitry 520 can include one or more massstorage devices, which can include, for example, a solid state diskdrive (SSDD), hard disk drive (HDD), a micro HDD, resistance changememories, phase change memories, holographic memories, or chemicalmemories, among others. In some implementations, the computer platform500 may incorporate the three-dimensional (3D) cross-point (XPOINT)memories from Intel® and Micron®.

The removable memory circuitry 523 can include devices, circuitry,enclosures, housings, ports or receptacles, among others, used to coupleportable data storage devices with the platform 500. These portable datastorage devices may be used for mass storage purposes, and can include,for example, flash memory cards (e.g., Secure Digital (SD) cards,microSD cards, xD picture cards), and USB flash drives, optical discs,or external HDDs, or combinations of them, among others.

The platform 500 may also include interface circuitry (not shown) forconnecting external devices with the platform 500. The external devicesconnected to the platform 500 using the interface circuitry includesensor circuitry 521 and electromechanical components (EMCs) 522, aswell as removable memory devices coupled to removable memory circuitry523.

The sensor circuitry 521 include devices, modules, or subsystems whosepurpose is to detect events or changes in its environment and send theinformation (e.g., sensor data) about the detected events to one or moreother devices, modules, or subsystems. Examples of such sensors includeinertial measurement units (IMUs) such as accelerometers, gyroscopes, ormagnetometers; microelectromechanical systems (MEMS) ornanoelectromechanical systems (NEMS) including 3-axis accelerometers,3-axis gyroscopes, or magnetometers; level sensors; flow sensors;temperature sensors (e.g., thermistors); pressure sensors; barometricpressure sensors; gravimeters; altimeters; image capture devices (e.g.,cameras or lensless apertures); light detection and ranging (LiDAR)sensors; proximity sensors (e.g., infrared radiation detector and thelike), depth sensors, ambient light sensors, ultrasonic transceivers;microphones or other audio capture devices, or combinations of them,among others.

The EMCs 522 include devices, modules, or subsystems whose purpose is toenable the platform 500 to change its state, position, or orientation,or move or control a mechanism, system, or subsystem. Additionally, theEMCs 522 may be configured to generate and send messages or signaling toother components of the platform 500 to indicate a current state of theEMCs 522. Examples of the EMCs 522 include one or more power switches,relays, such as electromechanical relays (EMRs) or solid state relays(SSRs), actuators (e.g., valve actuators), an audible sound generator, avisual warning device, motors (e.g., DC motors or stepper motors),wheels, thrusters, propellers, claws, clamps, hooks, or combinations ofthem, among other electromechanical components. In some implementations,the platform 500 is configured to operate one or more EMCs 522 based onone or more captured events, instructions, or control signals receivedfrom a service provider or clients, or both.

In some implementations, the interface circuitry may connect theplatform 500 with positioning circuitry 545. The positioning circuitry545 includes circuitry to receive and decode signals transmitted orbroadcasted by a positioning network of a GNSS. Examples of a GNSSinclude United States' GPS, Russia's GLONASS, the European Union'sGalileo system, China's BeiDou Navigation Satellite System, a regionalnavigation system or GNSS augmentation system (e.g., NAVIC), Japan'sQZSS, France's DORIS, among other systems. The positioning circuitry 545comprises various hardware elements (e.g., including hardware devicessuch as switches, filters, amplifiers, antenna elements, and the like tofacilitate OTA communications) to communicate with components of apositioning network, such as navigation satellite constellation nodes.In some implementations, the positioning circuitry 545 can include aMicro-PNT IC that uses a master timing clock to perform positiontracking or estimation without GNSS assistance. The positioningcircuitry 545 may also be part of, or interact with, the basebandcircuitry 410 or RFEMs 515, or both, to communicate with the nodes andcomponents of the positioning network. The positioning circuitry 545 mayalso provide data (e.g., position data, time data) to the applicationcircuitry 505, which may use the data to synchronize operations withvarious infrastructure (e.g., radio base stations), for turn-by-turnnavigation applications, or the like.

In some implementations, the interface circuitry may connect theplatform 500 with Near-Field Communication (NFC) circuitry 540. The NFCcircuitry 540 is configured to provide contactless, short-rangecommunications based on radio frequency identification (RFID) standards,in which magnetic field induction is used to enable communicationbetween NFC circuitry 540 and NFC-enabled devices external to theplatform 500 (e.g., an “NFC touchpoint”). The NFC circuitry 540 includesan NFC controller coupled with an antenna element and a processorcoupled with the NFC controller. The NFC controller may be a chip or ICproviding NFC functionalities to the NFC circuitry 540 by executing NFCcontroller firmware and an NFC stack. The NFC stack may be executed bythe processor to control the NFC controller, and the NFC controllerfirmware may be executed by the NFC controller to control the antennaelement to emit short-range RF signals. The RF signals may power apassive NFC tag (e.g., a microchip embedded in a sticker or wristband)to transmit stored data to the NFC circuitry 540, or initiate datatransfer between the NFC circuitry 540 and another active NFC device(e.g., a smartphone or an NFC-enabled POS terminal) that is proximate tothe platform 500.

The driver circuitry 546 can include software and hardware elements thatoperate to control particular devices that are embedded in the platform500, attached to the platform 500, or otherwise communicatively coupledwith the platform 500. The driver circuitry 546 can include individualdrivers allowing other components of the platform 500 to interact withor control various input/output (I/O) devices that may be presentwithin, or connected to, the platform 500. For example, the drivercircuitry 546 can include a display driver to control and allow accessto a display device, a touchscreen driver to control and allow access toa touchscreen interface of the platform 500, sensor drivers to obtainsensor readings of sensor circuitry 521 and control and allow access tosensor circuitry 521, EMC drivers to obtain actuator positions of theEMCs 522 or control and allow access to the EMCs 522, a camera driver tocontrol and allow access to an embedded image capture device, audiodrivers to control and allow access to one or more audio devices.

The power management integrated circuitry (PMIC) 525 (also referred toas “power management circuitry 525”) may manage power provided tovarious components of the platform 500. In particular, with respect tothe baseband circuitry 510, the PMIC 525 may control power-sourceselection, voltage scaling, battery charging, or DC-to-DC conversion.The PMIC 525 may be included when the platform 500 is capable of beingpowered by a battery 530, for example, when the device is included in aUE 101, 201, 301.

In some implementations, the PMIC 525 may control, or otherwise be partof, various power saving mechanisms of the platform 500. For example, ifthe platform 500 is in an RRC_Connected state, where it is stillconnected to the RAN node as it expects to receive traffic shortly, thenit may enter a state known as Discontinuous Reception Mode (DRX) after aperiod of inactivity. During this state, the platform 500 may power downfor brief intervals of time and thus save power. If there is no datatraffic activity for an extended period of time, then the platform 500may transition off to an RRC Idle state, where it disconnects from thenetwork and does not perform operations such as channel quality feedbackor handover. This can allow the platform 500 to enter a very low powerstate, where it periodically wakes up to listen to the network and thenpowers down again. In some implementations, the platform 500 may notreceive data in the RRC Idle state and instead must transition back toRRC_Connected state to receive data. An additional power saving mode mayallow a device to be unavailable to the network for periods longer thana paging interval (ranging from seconds to a few hours). During thistime, the device may be unreachable to the network and may power downcompletely. Any data sent during this time may incurs a large delay andit is assumed the delay is acceptable.

A battery 530 may power the platform 500, although In someimplementations the platform 500 may be deployed in a fixed location,and may have a power supply coupled to an electrical grid. The battery530 may be a lithium ion battery, a metal-air battery, such as azinc-air battery, an aluminum-air battery, or a lithium-air battery,among others. In some implementations, such as in V2X applications, thebattery 530 may be a typical lead-acid automotive battery.

In some implementations, the battery 530 may be a “smart battery,” whichincludes or is coupled with a Battery Management System (BMS) or batterymonitoring integrated circuitry. The BMS may be included in the platform500 to track the state of charge (SoCh) of the battery 530. The BMS maybe used to monitor other parameters of the battery 530 to providefailure predictions, such as the state of health (SoH) and the state offunction (SoF) of the battery 530. The BMS may communicate theinformation of the battery 530 to the application circuitry 505 or othercomponents of the platform 500. The BMS may also include ananalog-to-digital (ADC) convertor that allows the application circuitry505 to directly monitor the voltage of the battery 530 or the currentflow from the battery 530. The battery parameters may be used todetermine actions that the platform 500 may perform, such astransmission frequency, network operation, or sensing frequency, amongothers.

A power block, or other power supply coupled to an electrical grid maybe coupled with the BMS to charge the battery 530. In someimplementations, the power block 530 may be replaced with a wirelesspower receiver to obtain the power wirelessly, for example, through aloop antenna in the computer platform 500. In these examples, a wirelessbattery charging circuit may be included in the BMS. The specificcharging circuits chosen may depend on the size of the battery 530, andthus, the current required. The charging may be performed using theAirfuel standard promulgated by the Airfuel Alliance, the Qi wirelesscharging standard promulgated by the Wireless Power Consortium, or theRezence charging standard promulgated by the Alliance for WirelessPower, among others.

The user interface circuitry 550 includes various input/output (I/O)devices present within, or connected to, the platform 500, and includesone or more user interfaces designed to enable user interaction with theplatform 500 or peripheral component interfaces designed to enableperipheral component interaction with the platform 500. The userinterface circuitry 550 includes input device circuitry and outputdevice circuitry. Input device circuitry includes any physical orvirtual means for accepting an input including one or more physical orvirtual buttons (e.g., a reset button), a physical keyboard, keypad,mouse, touchpad, touchscreen, microphones, scanner, or headset, orcombinations of them, among others. The output device circuitry includesany physical or virtual means for showing information or otherwiseconveying information, such as sensor readings, actuator position(s), orother information. Output device circuitry can include any number orcombinations of audio or visual display, including one or more simplevisual outputs or indicators (e.g., binary status indicators (e.g.,light emitting diodes (LEDs)), multi-character visual outputs, or morecomplex outputs such as display devices or touchscreens (e.g., LiquidChrystal Displays (LCD), LED displays, quantum dot displays, orprojectors), with the output of characters, graphics, or multimediaobjects being generated or produced from the operation of the platform500. The output device circuitry may also include speakers or otheraudio emitting devices, or printer(s). In some implementations, thesensor circuitry 521 may be used as the input device circuitry (e.g., animage capture device or motion capture device), and one or more EMCs maybe used as the output device circuitry (e.g., an actuator to providehaptic feedback). In another example, NFC circuitry comprising an NFCcontroller coupled with an antenna element and a processing device maybe included to read electronic tags or connect with another NFC-enableddevice. Peripheral component interfaces can include, but are not limitedto, a non-volatile memory port, a USB port, an audio jack, or a powersupply interface.

Although not shown, the components of platform 500 may communicate withone another using a suitable bus or interconnect (IX) technology, whichcan include any number of technologies, including ISA, EISA, PCI, PCIx,PCIe, a Time-Trigger Protocol (TTP) system, a FlexRay system, or anynumber of other technologies. The bus or IX may be a proprietary bus orIX, for example, used in a SoC based system. Other bus or IX systems maybe included, such as an I2C interface, an SPI interface, point-to-pointinterfaces, and a power bus, among others.

FIG. 6 illustrates example components of baseband circuitry 610 andradio front end modules (RFEM) 615. The baseband circuitry 610 cancorrespond to the baseband circuitry 410 and 510 of FIGS. 4 and 5,respectively. The RFEM 615 can correspond to the RFEM 415 and 515 ofFIGS. 4 and 5, respectively. As shown, the RFEMs 615 can include RadioFrequency (RF) circuitry 606, front-end module (FEM) circuitry 608, andantenna array 611 coupled together.

The baseband circuitry 610 includes circuitry configured to carry outvarious radio or network protocol and control functions that enablecommunication with one or more radio networks using the RF circuitry606. The radio control functions can include, but are not limited to,signal modulation and demodulation, encoding and decoding, and radiofrequency shifting. In some implementations, modulation and demodulationcircuitry of the baseband circuitry 610 can include Fast-FourierTransform (FFT), precoding, or constellation mapping and demappingfunctionality. In some implementations, encoding and decoding circuitryof the baseband circuitry 610 can include convolution, tail-bitingconvolution, turbo, Viterbi, or Low Density Parity Check (LDPC) encoderand decoder functionality. Modulation and demodulation and encoder anddecoder functionality are not limited to these examples and can includeother suitable functionality in other examples. The baseband circuitry610 is configured to process baseband signals received from a receivesignal path of the RF circuitry 606 and to generate baseband signals fora transmit signal path of the RF circuitry 606. The baseband circuitry610 is configured to interface with application circuitry (e.g., theapplication circuitry 405, 505 shown in FIGS. 4 and 5) for generationand processing of the baseband signals and for controlling operations ofthe RF circuitry 606. The baseband circuitry 610 may handle variousradio control functions.

The aforementioned circuitry and control logic of the baseband circuitry610 can include one or more single or multi-core processors. Forexample, the one or more processors can include a 3G baseband processor604A, a 4G or LTE baseband processor 604B, a 5G or NR baseband processor604C, or some other baseband processor(s) 604D for other existinggenerations, generations in development or to be developed in the future(e.g., sixth generation (6G)). In some implementations, some or all ofthe functionality of baseband processors 604A-D may be included inmodules stored in the memory 604G and executed using a processor such asa Central Processing Unit (CPU) 604E. In some implementations, some orall of the functionality of baseband processors 604A-D may be providedas hardware accelerators (e.g., FPGAs or ASICs) loaded with theappropriate bit streams or logic blocks stored in respective memorycells. In some implementations, the memory 604G may store program codeof a real-time OS (RTOS) which, when executed by the CPU 604E (or otherbaseband processor), is to cause the CPU 604E (or other basebandprocessor) to manage resources of the baseband circuitry 610, scheduletasks, or carry out other operations. Examples of the RTOS can includeOperating System Embedded (OSE)™ provided by Enea®, Nucleus RTOS™provided by Mentor Graphics®, Versatile Real-Time Executive (VRTX)provided by Mentor Graphics®, ThreadX™ provided by Express Logic®,FreeRTOS, REX OS provided by Qualcomm®, OKL4 provided by Open Kernel(OK) Labs®, or any other suitable RTOS, such as those discussed herein.In addition, the baseband circuitry 610 includes one or more audiodigital signal processor(s) (DSP) 604F. The audio DSP(s) 604F includeelements for compression and decompression and echo cancellation and caninclude other suitable processing elements.

In some implementations, each of the processors 604A-604E includerespective memory interfaces to send and receive data to and from thememory 604G. The baseband circuitry 610 may further include one or moreinterfaces to communicatively couple to other circuitries or devices,such as an interface to send and receive data to and from memoryexternal to the baseband circuitry 610; an application circuitryinterface to send and receive data to and from the application circuitry405, 505 of FIGS. 4 and 5); an RF circuitry interface to send andreceive data to and from RF circuitry 606 of FIG. 6; a wireless hardwareconnectivity interface to send and receive data to and from one or morewireless hardware elements (e.g., Near Field Communication (NFC)components, Bluetooth®/Bluetooth® Low Energy components, Wi-Ficomponents, and/or the like); and a power management interface to sendand receive power or control signals to and from the PMIC 525.

In some implementations (which may be combined with the above describedexamples), the baseband circuitry 610 includes one or more digitalbaseband systems, which are coupled with one another using aninterconnect subsystem and to a CPU subsystem, an audio subsystem, andan interface subsystem. The digital baseband subsystems may also becoupled to a digital baseband interface and a mixed-signal basebandsubsystem using another interconnect subsystem. Each of the interconnectsubsystems can include a bus system, point-to-point connections,network-on-chip (NOC) structures, or some other suitable bus orinterconnect technology, such as those discussed herein. The audiosubsystem can include DSP circuitry, buffer memory, program memory,speech processing accelerator circuitry, data converter circuitry suchas analog-to-digital and digital-to-analog converter circuitry, analogcircuitry including one or more of amplifiers and filters, among othercomponents. In some implementations, the baseband circuitry 610 caninclude protocol processing circuitry with one or more instances ofcontrol circuitry (not shown) to provide control functions for thedigital baseband circuitry or radio frequency circuitry (e.g., the radiofront end modules 615).

Although not shown in FIG. 6, In some implementations, the basebandcircuitry 610 includes individual processing device(s) to operate one ormore wireless communication protocols (e.g., a “multi-protocol basebandprocessor” or “protocol processing circuitry”) and individual processingdevice(s) to implement PI—W layer functions. In some implementations,the PHY layer functions include the aforementioned radio controlfunctions. In some implementations, the protocol processing circuitryoperates or implements various protocol layers or entities of one ormore wireless communication protocols. For example, the protocolprocessing circuitry may operate LTE protocol entities or 5G NR protocolentities, or both, when the baseband circuitry 610 or RF circuitry 606,or both, are part of mmWave communication circuitry or some othersuitable cellular communication circuitry. In this example, the protocolprocessing circuitry can operate MAC, RLC, PDCP, SDAP, RRC, and NASfunctions. In some implementations, the protocol processing circuitrymay operate one or more IEEE-based protocols when the baseband circuitry610 or RF circuitry 606, or both, are part of a Wi-Fi communicationsystem. In this example, the protocol processing circuitry can operateWi-Fi MAC and logical link control (LLC) functions. The protocolprocessing circuitry can include one or more memory structures (e.g.,604G) to store program code and data for operating the protocolfunctions, as well as one or more processing cores to execute theprogram code and perform various operations using the data. The basebandcircuitry 610 may also support radio communications for more than onewireless protocol.

The various hardware elements of the baseband circuitry 610 discussedherein may be implemented, for example, as a solder-down substrateincluding one or more integrated circuits (ICs), a single packaged ICsoldered to a main circuit board or a multi-chip module containing twoor more ICs. In some implementations, the components of the basebandcircuitry 610 may be suitably combined in a single chip or chipset, ordisposed on a same circuit board. In some implementations, some or allof the constituent components of the baseband circuitry 610 and RFcircuitry 606 may be implemented together such as, for example, a systemon a chip (SoC) or System-in-Package (SiP). In some implementations,some or all of the constituent components of the baseband circuitry 610may be implemented as a separate SoC that is communicatively coupledwith and RF circuitry 606 (or multiple instances of RF circuitry 606).In some implementations, some or all of the constituent components ofthe baseband circuitry 610 and the application circuitry 405, 505 may beimplemented together as individual SoCs mounted to a same circuit board(e.g., a “multi-chip package”).

In some implementations, the baseband circuitry 610 may provide forcommunication compatible with one or more radio technologies. Forexample, the baseband circuitry 610 may support communication with anE-UTRAN or other WMAN, a WLAN, or a WPAN. Examples in which the basebandcircuitry 610 is configured to support radio communications of more thanone wireless protocol may be referred to as multi-mode basebandcircuitry.

The RF circuitry 606 may enable communication with wireless networksusing modulated electromagnetic radiation through a non-solid medium. Insome implementations, the RF circuitry 606 can include switches,filters, or amplifiers, among other components, to facilitate thecommunication with the wireless network. The RF circuitry 606 caninclude a receive signal path, which can include circuitry todown-convert RF signals received from the FEM circuitry 608 and providebaseband signals to the baseband circuitry 610. The RF circuitry 606 mayalso include a transmit signal path, which can include circuitry toup-convert baseband signals provided by the baseband circuitry 610 andprovide RF output signals to the FEM circuitry 608 for transmission.

The receive signal path of the RF circuitry 606 includes mixer circuitry606 a, amplifier circuitry 606 b and filter circuitry 606 c. In someimplementations, the transmit signal path of the RF circuitry 606 caninclude filter circuitry 606 c and mixer circuitry 606 a. The RFcircuitry 606 also includes synthesizer circuitry 606 d for synthesizinga frequency for use by the mixer circuitry 606 a of the receive signalpath and the transmit signal path. In some implementations, the mixercircuitry 606 a of the receive signal path may be configured todown-convert RF signals received from the FEM circuitry 608 based on thesynthesized frequency provided by synthesizer circuitry 606 d. Theamplifier circuitry 606 b may be configured to amplify thedown-converted signals and the filter circuitry 606 c may be a low-passfilter (LPF) or band-pass filter (BPF) configured to remove unwantedsignals from the down-converted signals to generate output basebandsignals. Output baseband signals may be provided to the basebandcircuitry 610 for further processing. In some implementations, theoutput baseband signals may be zero-frequency baseband signals, althoughthis is not a requirement. In some implementations, the mixer circuitry606 a of the receive signal path may comprise passive mixers.

In some implementations, the mixer circuitry 606 a of the transmitsignal path may be configured to up-convert input baseband signals basedon the synthesized frequency provided by the synthesizer circuitry 606 dto generate RF output signals for the FEM circuitry 608. The basebandsignals may be provided by the baseband circuitry 610 and may befiltered by filter circuitry 606 c.

In some implementations, the mixer circuitry 606 a of the receive signalpath and the mixer circuitry 606 a of the transmit signal path caninclude two or more mixers and may be arranged for quadraturedownconversion and upconversion, respectively. In some implementations,the mixer circuitry 606 a of the receive signal path and the mixercircuitry 606 a of the transmit signal path can include two or moremixers and may be arranged for image rejection (e.g., Hartley imagerejection). In some implementations, the mixer circuitry 606 a of thereceive signal path and the mixer circuitry 606 a of the transmit signalpath may be arranged for direct downconversion and direct upconversion,respectively. In some implementations, the mixer circuitry 606 a of thereceive signal path and the mixer circuitry 606 a of the transmit signalpath may be configured for super-heterodyne operation.

In some implementations, the output baseband signals and the inputbaseband signals may be analog baseband signals. In someimplementations, the output baseband signals and the input basebandsignals may be digital baseband signals, and the RF circuitry 606 caninclude analog-to-digital converter (ADC) and digital-to-analogconverter (DAC) circuitry and the baseband circuitry 610 can include adigital baseband interface to communicate with the RF circuitry 606.

In some dual-mode examples, a separate radio IC circuitry may beprovided for processing signals for each spectrum, although thetechniques described here are not limited in this respect.

In some implementations, the synthesizer circuitry 606 d may be afractional-N synthesizer or a fractional N/N+1 synthesizer, althoughother types of frequency synthesizers may used. For example, synthesizercircuitry 606 d may be a delta-sigma synthesizer, a frequencymultiplier, or a synthesizer comprising a phase-locked loop with afrequency divider.

The synthesizer circuitry 606 d may be configured to synthesize anoutput frequency for use by the mixer circuitry 606 a of the RFcircuitry 606 based on a frequency input and a divider control input. Insome implementations, the synthesizer circuitry 606 d may be afractional N/N+1 synthesizer.

In some implementations, frequency input may be provided by a voltagecontrolled oscillator (VCO), although that is not a requirement. Dividercontrol input may be provided by either the baseband circuitry 610 orthe application circuitry 405/505 depending on the desired outputfrequency. In some implementations, a divider control input (e.g., N)may be determined from a look-up table based on a channel indicated bythe application circuitry 405, 505.

The synthesizer circuitry 606 d of the RF circuitry 606 can include adivider, a delay-locked loop (DLL), a multiplexer and a phaseaccumulator. In some implementations, the divider may be a dual modulusdivider (DMD) and the phase accumulator may be a digital phaseaccumulator (DPA). In some implementations, the DMD may be configured todivide the input signal by either N or N+1 (e.g., based on a carry out)to provide a fractional division ratio. In some implementations, the DLLcan include a set of cascaded, tunable, delay elements, a phasedetector, a charge pump and a D-type flip-flop. The delay elements maybe configured to break a VCO period up into Nd equal packets of phase,where Nd is the number of delay elements in the delay line. In this way,the DLL provides negative feedback to help ensure that the total delaythrough the delay line is one VCO cycle.

In some implementations, synthesizer circuitry 606 d may be configuredto generate a carrier frequency as the output frequency, while in otherexamples, the output frequency may be a multiple of the carrierfrequency (e.g., twice the carrier frequency, four times the carrierfrequency) and used in conjunction with quadrature generator and dividercircuitry to generate multiple signals at the carrier frequency withmultiple different phases with respect to each other. In someimplementations, the output frequency may be a LO frequency (fLO). Insome implementations, the RF circuitry 606 can include an IQ or polarconverter.

The FEM circuitry 608 can include a receive signal path, which caninclude circuitry configured to operate on RF signals received fromantenna array 611, amplify the received signals and provide theamplified versions of the received signals to the RF circuitry 606 forfurther processing. The FEM circuitry 608 may also include a transmitsignal path, which can include circuitry configured to amplify signalsfor transmission provided by the RF circuitry 606 for transmission byone or more of antenna elements of antenna array 611. The amplificationthrough the transmit or receive signal paths may be done solely in theRF circuitry 606, solely in the FEM circuitry 608, or in both the RFcircuitry 606 and the FEM circuitry 608.

In some implementations, the FEM circuitry 608 can include a TX/RXswitch to switch between transmit mode and receive mode operation. TheFEM circuitry 608 can include a receive signal path and a transmitsignal path. The receive signal path of the FEM circuitry 608 caninclude an LNA to amplify received RF signals and provide the amplifiedreceived RF signals as an output (e.g., to the RF circuitry 606). Thetransmit signal path of the FEM circuitry 608 can include a poweramplifier (PA) to amplify input RF signals (e.g., provided by RFcircuitry 606), and one or more filters to generate RF signals forsubsequent transmission by one or more antenna elements of the antennaarray 611.

The antenna array 611 comprises one or more antenna elements, each ofwhich is configured convert electrical signals into radio waves totravel through the air and to convert received radio waves intoelectrical signals. For example, digital baseband signals provided bythe baseband circuitry 610 is converted into analog RF signals (e.g.,modulated waveform) that will be amplified and transmitted using theantenna elements of the antenna array 611 including one or more antennaelements (not shown). The antenna elements may be omnidirectional,directional, or a combination thereof. The antenna elements may beformed in a multitude of arranges as are known and/or discussed herein.The antenna array 611 may comprise microstrip antennas or printedantennas that are fabricated on the surface of one or more printedcircuit boards. The antenna array 611 may be formed as a patch of metalfoil (e.g., a patch antenna) in a variety of shapes, and may be coupledwith the RF circuitry 606 and/or FEM circuitry 608 using metaltransmission lines or the like.

Processors of the application circuitry 405/505 and processors of thebaseband circuitry 610 may be used to execute elements of one or moreinstances of a protocol stack. For example, processors of the basebandcircuitry 610, alone or in combination, may execute Layer 3, Layer 2, orLayer 1 functionality, while processors of the application circuitry405, 505 may utilize data (e.g., packet data) received from these layersand further execute Layer 4 functionality (e.g., TCP and UDP layers). Asreferred to herein, Layer 3 may comprise a RRC layer, described infurther detail below. As referred to herein, Layer 2 may comprise a MAClayer, an RLC layer, and a PDCP layer, described in further detailbelow. As referred to herein, Layer 1 may comprise a PHY layer of aUE/RAN node, described in further detail below.

FIG. 7 illustrates example components of communication circuitry 700. Insome implementations, the communication circuitry 700 may be implementedas part of the system 400 or the platform 500 shown in FIGS. 4 and 5.The communication circuitry 700 may be communicatively coupled (e.g.,directly or indirectly) to one or more antennas, such as antennas 711A,711B, 711C, and 711D. In some implementations, the communicationcircuitry 700 includes or is communicatively coupled to dedicatedreceive chains, processors, or radios, or combinations of them, formultiple RATs (e.g., a first receive chain for LTE and a second receivechain for 5G NR). For example, as shown in FIG. 7, the communicationcircuitry 700 includes a modem 710 and a modem 720, which may correspondto or be a part of the baseband circuitry 410 and 510 of FIGS. 4 and 5.The modem 710 may be configured for communications according to a firstRAT, such as LTE or LTE-A, and the modem 720 may be configured forcommunications according to a second RAT, such as 5G NR. In someimplementations, a processor 705, such as an application processor, caninterface with the modems 710, 720.

The modem 710 includes one or more processors 712 and a memory 716 incommunication with the processors 712. The modem 710 is in communicationwith a radio frequency (RF) front end 730, which may correspond to or bea part of to the RFEM 415 and 515 of FIGS. 4 and 5. The RF front end 730can include circuitry for transmitting and receiving radio signals. Forexample, the RF front end 730 includes receive circuitry (RX) 732 andtransmit circuitry (TX) 734. In some implementations, the receivecircuitry 732 is in communication with a DL front end 752, which caninclude circuitry for receiving radio signals from one or more antennas711A. The transmit circuitry 734 is in communication with a UL front end754, which is coupled with one or more antennas 711B.

Similarly, the modem 720 includes one or more processors 722 and amemory 726 in communication with the one or more processors 722. Themodem 720 is in communication with an RF front end 740, which maycorrespond to or be a part of to the RFEM 415 and 515 of FIGS. 4 and 5.The RF front end 740 can include circuitry for transmitting andreceiving radio signals. For example, the RF front end 740 includesreceive circuitry 742 and transmit circuitry 744. In someimplementations, the receive circuitry 742 is in communication with a DLfront end 760, which can include circuitry for receiving radio signalsfrom one or more antennas 711C. The transmit circuitry 744 is incommunication with a UL front end 765, which is coupled with one or moreantennas 711D. In some implementations, one or more front-ends can becombined. For example, a RF switch can selectively couple the modems710, 720 to a single UL front end 772 for transmitting radio signalsusing one or more antennas.

The processors 712, 722 can include one or more processing elementsconfigured to implement various features described herein, such as byexecuting program instructions stored on the memory 716, 726 (e.g., anon-transitory computer-readable memory medium). In someimplementations, the processor 712, 722 may be configured as aprogrammable hardware element, such as a FPGA or an ASIC. In someimplementations, the processors 712, 722 can include one or more ICsthat are configured to perform the functions of processors 712, 722.

FIG. 8 illustrates various protocol functions that may be implemented ina wireless communication device. In particular, FIG. 8 includes anarrangement 800 showing interconnections between various protocollayers/entities. The following description of FIG. 8 is provided forvarious protocol layers and entities that operate in conjunction withthe 5G NR system standards and the LTE system standards, but some or allof the aspects of FIG. 8 may be applicable to other wirelesscommunication network systems as well.

The protocol layers of arrangement 800 can include one or more of PHY810, MAC 820, RLC 830, PDCP 840, SDAP 847, RRC 855, and NAS layer 857,in addition to other higher layer functions not illustrated. Theprotocol layers can include one or more service access points (e.g.,items 859, 856, 850, 849, 845, 835, 825, and 815 in FIG. 8) that mayprovide communication between two or more protocol layers.

The PHY 810 may transmit and receive physical layer signals 805 that maybe received from or transmitted to one or more other communicationdevices. The physical layer signals 805 can include one or more physicalchannels, such as those discussed herein. The PHY 810 may furtherperform link adaptation or adaptive modulation and coding (AMC), powercontrol, cell search (e.g., for initial synchronization and handoverpurposes), and other measurements used by higher layers, such as the RRC855. The PHY 810 may still further perform error detection on thetransport channels, forward error correction (FEC) coding and decodingof the transport channels, modulation and demodulation of physicalchannels, interleaving, rate matching, mapping onto physical channels,and MIMO antenna processing. In some implementations, an instance of PHY810 may process requests from and provide indications to an instance ofMAC 820 using one or more PHY-SAP 815. In some implementations, requestsand indications communicated using PHY-SAP 815 may comprise one or moretransport channels.

Instance(s) of MAC 820 may process requests from, and provideindications to, an instance of RLC 830 using one or more MAC-SAPs 825.These requests and indications communicated using the MAC-SAP 825 caninclude one or more logical channels. The MAC 820 may perform mappingbetween the logical channels and transport channels, multiplexing of MACSDUs from one or more logical channels onto transport blocks (TBs) to bedelivered to PHY 810 using the transport channels, de-multiplexing MACSDUs to one or more logical channels from TBs delivered from the PHY 810using transport channels, multiplexing MAC SDUs onto TBs, schedulinginformation reporting, error correction through HARQ, and logicalchannel prioritization.

Instance(s) of RLC 830 may process requests from and provide indicationsto an instance of PDCP 840 using one or more radio link control serviceaccess points (RLC-SAP) 835. These requests and indications communicatedusing RLC-SAP 835 can include one or more RLC channels. The RLC 830 mayoperate in a plurality of modes of operation, including: TransparentMode™, Unacknowledged Mode (UM), and Acknowledged Mode (AM). The RLC 830may execute transfer of upper layer protocol data units (PDUs), errorcorrection through automatic repeat request (ARQ) for AM data transfers,and concatenation, segmentation and reassembly of RLC SDUs for UM and AMdata transfers. The RLC 830 may also execute re-segmentation of RLC dataPDUs for AM data transfers, reorder RLC data PDUs for UM and AM datatransfers, detect duplicate data for UM and AM data transfers, discardRLC SDUs for UM and AM data transfers, detect protocol errors for AMdata transfers, and perform RLC re-establishment.

Instance(s) of PDCP 840 may process requests from and provideindications to instance(s) of RRC 855 or instance(s) of SDAP 847, orboth, using one or more packet data convergence protocol service accesspoints (PDCP-SAP) 845. These requests and indications communicated usingPDCP-SAP 845 can include one or more radio bearers. The PDCP 840 mayexecute header compression and decompression of IP data, maintain PDCPSequence Numbers (SNs), perform in-sequence delivery of upper layer PDUsat re-establishment of lower layers, eliminate duplicates of lower layerSDUs at re-establishment of lower layers for radio bearers mapped on RLCAM, cipher and decipher control plane data, perform integrity protectionand integrity verification of control plane data, control timer-baseddiscard of data, and perform security operations (e.g., ciphering,deciphering, integrity protection, or integrity verification).

Instance(s) of SDAP 847 may process requests from and provideindications to one or more higher layer protocol entities using one ormore SDAP-SAP 849. These requests and indications communicated usingSDAP-SAP 849 can include one or more QoS flows. The SDAP 847 may map QoSflows to data radio bearers (DRBs), and vice versa, and may also markQoS flow identifiers (QFIs) in DL and UL packets. A single SDAP entity847 may be configured for an individual PDU session. In the ULdirection, the NG-RAN 110 may control the mapping of QoS Flows to DRB(s)in two different ways, reflective mapping or explicit mapping. Forreflective mapping, the SDAP 847 of a UE 101 may monitor the QFIs of theDL packets for each DRB, and may apply the same mapping for packetsflowing in the UL direction. For a DRB, the SDAP 847 of the UE 101 maymap the UL packets belonging to the QoS flows(s) corresponding to theQoS flow ID(s) and PDU session observed in the DL packets for that DRB.To enable reflective mapping, the NG-RAN 310 may mark DL packets overthe Uu interface with a QoS flow ID. The explicit mapping may involvethe RRC 855 configuring the SDAP 847 with an explicit QoS flow to DRBmapping rule, which may be stored and followed by the SDAP 847. In someimplementations, the SDAP 847 may only be used in NR implementations andmay not be used in LTE implementations.

The RRC 855 may configure, using one or more management service accesspoints (M-SAP), aspects of one or more protocol layers, which caninclude one or more instances of PHY 810, MAC 820, RLC 830, PDCP 840 andSDAP 847. In some implementations, an instance of RRC 855 may processrequests from and provide indications to one or more NAS entities 857using one or more RRC-SAPs 856. The main services and functions of theRRC 855 can include broadcast of system information (e.g., included inmaster information blocks (MIBs) or system information blocks (SIBs)related to the NAS), broadcast of system information related to theaccess stratum (AS), paging, establishment, maintenance and release ofan RRC connection between the UE 101 and RAN 110 (e.g., RRC connectionpaging, RRC connection establishment, RRC connection modification, andRRC connection release), establishment, configuration, maintenance andrelease of point to point Radio Bearers, security functions includingkey management, inter-RAT mobility, and measurement configuration for UEmeasurement reporting. The MIBs and SIBs may comprise one or moreinformation elements, which may each comprise individual data fields ordata structures.

The NAS 857 may form the highest stratum of the control plane betweenthe UE 101 and the AMF 321. The NAS 857 may support the mobility of theUEs 101 and the session management procedures to establish and maintainIP connectivity between the UE 101 and a P-GW in LTE systems.

In some implementations, one or more protocol entities of arrangement800 may be implemented in UEs 101, RAN nodes 111, AMF 321 in NRimplementations or MME 221 in LTE implementations, UPF 302 in NRimplementations or S-GW 222 and P-GW 223 in LTE implementations, or thelike to be used for control plane or user plane communications protocolstack between the aforementioned devices. In some implementations, oneor more protocol entities that may be implemented in one or more of UE101, gNB 111, AMF 321, among others, may communicate with a respectivepeer protocol entity that may be implemented in or on another deviceusing the services of respective lower layer protocol entities toperform such communication. In some implementations, a gNB-CU of the gNB111 may host the RRC 855, SDAP 847, and PDCP 840 of the gNB thatcontrols the operation of one or more gNB-DUs, and the gNB-DUs of thegNB 111 may each host the RLC 830, MAC 820, and PHY 810 of the gNB 111.

In some implementations, a control plane protocol stack can include, inorder from highest layer to lowest layer, NAS 857, RRC 855, PDCP 840,RLC 830, MAC 820, and PHY 810. In this example, upper layers 860 may bebuilt on top of the NAS 857, which includes an IP layer 861, an SCTP862, and an application layer signaling protocol (AP) 863.

In some implementations, such as NR implementations, the AP 863 may bean NG application protocol layer (NGAP or NG-AP) 863 for the NGinterface 113 defined between the NG-RAN node 111 and the AMF 321, orthe AP 863 may be an Xn application protocol layer (XnAP or Xn-AP) 863for the Xn interface 112 that is defined between two or more RAN nodes111.

The NG-AP 863 may support the functions of the NG interface 113 and maycomprise elementary procedures (EPs). An NG-AP EP may be a unit ofinteraction between the NG-RAN node 111 and the AMF 321. The NG-AP 863services can include two groups: UE-associated services (e.g., servicesrelated to a UE 101) and non-UE-associated services (e.g., servicesrelated to the whole NG interface instance between the NG-RAN node 111and AMF 321). These services can include functions such as, but notlimited to: a paging function for the sending of paging requests toNG-RAN nodes 111 involved in a particular paging area; a UE contextmanagement function for allowing the AMF 321 to establish, modify, orrelease a UE context in the AMF 321 and the NG-RAN node 111; a mobilityfunction for UEs 101 in ECM-CONNECTED mode for intra-system HOs tosupport mobility within NG-RAN and inter-system HOs to support mobilityfrom/to EPS systems; a NAS Signaling Transport function for transportingor rerouting NAS messages between UE 101 and AMF 321; a NAS nodeselection function for determining an association between the AMF 321and the UE 101; NG interface management function(s) for setting up theNG interface and monitoring for errors over the NG interface; a warningmessage transmission function for providing means to transfer warningmessages using NG interface or cancel ongoing broadcast of warningmessages; a configuration transfer function for requesting andtransferring of RAN configuration information (e.g., SON information orperformance measurement (PM) data) between two RAN nodes 111 using CN120, or combinations of them, among others.

The XnAP 863 may support the functions of the Xn interface 112 and maycomprise XnAP basic mobility procedures and XnAP global procedures. TheXnAP basic mobility procedures may comprise procedures used to handle UEmobility within the NG RAN 111 (or E-UTRAN 210), such as handoverpreparation and cancellation procedures, SN Status Transfer procedures,UE context retrieval and UE context release procedures, RAN pagingprocedures, or dual connectivity related procedures, among others. TheXnAP global procedures may comprise procedures that are not related to aspecific UE 101, such as Xn interface setup and reset procedures, NG-RANupdate procedures, or cell activation procedures, among others.

In LTE implementations, the AP 863 may be an S1 Application Protocollayer (S1-AP) 863 for the S1 interface 113 defined between an E-UTRANnode 111 and an MME, or the AP 863 may be an X2 application protocollayer (X2AP or X2-AP) 863 for the X2 interface 112 that is definedbetween two or more E-UTRAN nodes 111.

The S1 Application Protocol layer (S1-AP) 863 may support the functionsof the S1 interface, and similar to the NG-AP discussed previously, theS1-AP can include S1-AP EPs. An S1-AP EP may be a unit of interactionbetween the E-UTRAN node 111 and an MME 221 within an LTE CN 120. TheS1-AP 863 services may comprise two groups: UE-associated services andnon UE-associated services. These services perform functions including,but not limited to: E-UTRAN Radio Access Bearer (E-RAB) management, UEcapability indication, mobility, NAS signaling transport, RANInformation Management (RIM), and configuration transfer.

The X2AP 863 may support the functions of the X2 interface 112 and caninclude X2AP basic mobility procedures and X2AP global procedures. TheX2AP basic mobility procedures can include procedures used to handle UEmobility within the E-UTRAN 120, such as handover preparation andcancellation procedures, SN Status Transfer procedures, UE contextretrieval and UE context release procedures, RAN paging procedures, ordual connectivity related procedures, among others. The X2AP globalprocedures may comprise procedures that are not related to a specific UE101, such as X2 interface setup and reset procedures, load indicationprocedures, error indication procedures, or cell activation procedures,among others.

The SCTP layer (alternatively referred to as the SCTP/IP layer) 862 mayprovide guaranteed delivery of application layer messages (e.g., NGAP orXnAP messages in NR implementations, or 1-AP or X2AP messages in LTEimplementations). The SCTP 862 may ensure reliable delivery of signalingmessages between the RAN node 111 and the AMF 321/MME 221 based in parton the IP protocol, supported by the IP 861. The Internet Protocol layer(IP) 861 may be used to perform packet addressing and routingfunctionality. In some implementations the IP layer 861 may usepoint-to-point transmission to deliver and convey PDUs. In this regard,the RAN node 111 can include L2 and L1 layer communication links (e.g.,wired or wireless) with the MME/AMF to exchange information.

In some implementations, a user plane protocol stack can include, inorder from highest layer to lowest layer, SDAP 847, PDCP 840, RLC 830,MAC 820, and PHY 810. The user plane protocol stack may be used forcommunication between the UE 101, the RAN node 111, and UPF 302 in NRimplementations or an S-GW 222 and P-GW 223 in LTE implementations. Inthis example, upper layers 851 may be built on top of the SDAP 847, andcan include a user datagram protocol (UDP) and IP security layer(UDP/IP) 852, a General Packet Radio Service (GPRS) Tunneling Protocolfor the user plane layer (GTP-U) 853, and a User Plane PDU layer (UPPDU) 863.

The transport network layer 854 (also referred to as a “transportlayer”) may be built on IP transport, and the GTP-U 853 may be used ontop of the UDP/IP layer 852 (comprising a UDP layer and IP layer) tocarry user plane PDUs (UP-PDUs). The IP layer (also referred to as the“Internet layer”) may be used to perform packet addressing and routingfunctionality. The IP layer may assign IP addresses to user data packetsin any of IPv4, IPv6, or PPP formats, for example.

The GTP-U 853 may be used for carrying user data within the GPRS corenetwork and between the radio access network and the core network. Theuser data transported can be packets in any of IPv4, IPv6, or PPPformats, for example. The UDP/IP 852 may provide checksums for dataintegrity, port numbers for addressing different functions at the sourceand destination, and encryption and authentication on the selected dataflows. The RAN node 111 and the S-GW 222 may utilize an S1-U interfaceto exchange user plane data using a protocol stack comprising an L1layer (e.g., PHY 810), an L2 layer (e.g., MAC 820, RLC 830, PDCP 840,and/or SDAP 847), the UDP/IP layer 852, and the GTP-U 853. The S-GW 222and the P-GW 223 may utilize an S5/S8a interface to exchange user planedata using a protocol stack comprising an L1 layer, an L2 layer, theUDP/IP layer 852, and the GTP-U 853. As discussed previously, NASprotocols may support the mobility of the UE 101 and the sessionmanagement procedures to establish and maintain IP connectivity betweenthe UE 101 and the P-GW 223.

Moreover, although not shown by FIG. 8, an application layer may bepresent above the AP 863 and/or the transport network layer 854. Theapplication layer may be a layer in which a user of the UE 101, RAN node111, or other network element interacts with software applications beingexecuted, for example, by application circuitry 405 or applicationcircuitry 505, respectively. The application layer may also provide oneor more interfaces for software applications to interact withcommunications systems of the UE 101 or RAN node 111, such as thebaseband circuitry 610. In some implementations, the IP layer or theapplication layer, or both, may provide the same or similarfunctionality as layers 5-7, or portions thereof, of the Open SystemsInterconnection (OSI) model (e.g., OSI Layer 7—the application layer,OSI Layer 6—the presentation layer, and OSI Layer 5—the session layer).

NFV architectures and infrastructures may be used to virtualize one ormore NFs, alternatively performed by proprietary hardware, onto physicalresources comprising a combination of industry-standard server hardware,storage hardware, or switches. In other words, NFV systems can be usedto execute virtual or reconfigurable implementations of one or more EPCcomponents and functions.

FIG. 9 illustrates a block diagram of example of a computer system thatincludes components for reading instructions from a machine-readable orcomputer-readable medium (e.g., a non-transitory machine-readablestorage medium) and performing any one or more of the techniquesdescribed herein. In this example, FIG. 9 shows a diagrammaticrepresentation of hardware resources 900 including one or moreprocessors (or processor cores) 910, one or more memory or storagedevices 920, and one or more communication resources 930, each of whichmay be communicatively coupled using a bus 940. For implementationswhere node virtualization (e.g., NFV) is utilized, a hypervisor 902 maybe executed to provide an execution environment for one or more networkslices or sub-slices to utilize the hardware resources 900.

The processors 910 can include a processor 912 and a processor 914. Theprocessor(s) 910 may be, for example, a central processing unit (CPU), areduced instruction set computing (RISC) processor, a complexinstruction set computing (CISC) processor, a graphics processing unit(GPU), a DSP such as a baseband processor, an ASIC, an FPGA, aradio-frequency integrated circuit (RFIC), another processor (includingthose discussed herein), or any suitable combination thereof.

The memory/storage devices 920 can include main memory, disk storage, orany suitable combination thereof. The memory/storage devices 920 caninclude, but are not limited to, any type of volatile or nonvolatilememory such as dynamic random access memory (DRAM), static random accessmemory (SRAM), erasable programmable read-only memory (EPROM),electrically erasable programmable read-only memory (EEPROM), Flashmemory, or solid-state storage, or combinations of them, among others.

The communication resources 930 can include interconnection or networkinterface components or other suitable devices to communicate with oneor more peripheral devices 904 or one or more databases 906 using anetwork 908. For example, the communication resources 930 can includewired communication components (e.g., for coupling using USB), cellularcommunication components, NFC components, Bluetooth® (or Bluetooth® LowEnergy) components, Wi-Fi components, and other communicationcomponents.

Instructions 950 may comprise software, a program, an application, anapplet, an app, or other executable code for causing at least any of theprocessors 910 to perform any one or more of the methodologies discussedherein. The instructions 950 may reside, completely or partially, withinat least one of the processors 910 (e.g., within the processor's cachememory), the memory/storage devices 920, or any suitable combinationthereof. Furthermore, any portion of the instructions 950 may betransferred to the hardware resources 900 from any combination of theperipheral devices 904 or the databases 906. Accordingly, the memory ofprocessors 910, the memory/storage devices 920, the peripheral devices904, and the databases 906 are examples of computer-readable andmachine-readable media.

RRC states for UE can include an idle state and a connected state. TheRRC states can also include an inactive state where the UE is registeredwith the network but not actively transmitting data. A resume procedurecan prepare a UE for subsequent data transmission by causing the UE toswitch from an inactive state to a connected state. In 5G NR, the RRCstates for a 5G NR enabled UE can include RRC IDLE, RRC_INACTIVE, andRRC_CONNECTED states. When not transmitting data in a RRC_CONNECTEDstate, the UE can switch to a RRC_INACTIVE state but remain registeredwith the network.

FIG. 10 illustrates an example of a resume procedure for a small datatransmission. In this example, a wireless system includes a UE, RANnodes (old RAN node and new RAN node), and a device providing a UPF.From time to time, the UE may need to transmit a small amount of data.In this example, the UE's context is stored at the old RAN, which can bethe “anchor” for the UE. However, the UE starts to communicate with anew RAN. The UE, in the RRC_INACTIVE state, sends a RRC resume requestto the new RAN node at 1001. At 1002, the new RAN node and the old RANnode perform a UE context retrieval and forward tunnel establishmentprocedure. At 1003, the new RAN node sends a RRC resume message to theUE, which causes the UE to enter the RRC_CONNECTED state. At 1004, smalldata delivery commences. At 1005, the UE and new RAN node perform aconnection inactive procedure. A connection inactive procedure caninclude causing the UE to switch back to a RRC_INACTIVE state.

The present disclosure describes among other things, techniques tosupport frequent small data transmissions that enable the UE to switchfrom an inactive state to a connected state to perform a small datatransmission. Moreover, techniques are disclosed that do not requirepath switching when a UE resumes transmitting data. As such, a wirelesscommunication system can provide one or more signaling mechanisms tosupport frequent small data transmissions after a resume procedure isperformed. This can be performed without path switching. These signalingmechanisms can be triggered by a UE transmitting a small data indicationin a resume request. The one or more signaling mechanisms provided inthis disclosure can enable a node such as a NG-RAN to support frequentsmall data transmissions for various applications, such as CIoT-basedapplications, after a resume procedure is performed. In someimplementations, a small data transmission can be appropriate for datatransmissions that do not exceed a predetermined threshold, e.g., ULtransmissions that are less than N bytes, where N is a predeterminedvalue, e.g., 100, 128, 256, 512, and 1024. Other values for N arepossible.

A signaling mechanism can include the old RAN transmitting a RRC releaseconfiguration or message to the new RAN via a context retrievalprocedure. The UE indicates its small data intention upon resumption tothe new RAN. This indication is forwarded from the new RAN to the oldRAN. In turn, the old RAN provides a RRC release configuration ormessage to the new RAN during context retrieval. After UL or DL datatransfer, the new RAN further informs the old RAN that the UE isreleased and informs the old RAN not to send DL data anymore. The newRAN may send the UE Context back to the anchor, if the configuration forthe UE Context has been changed.

Another signaling mechanism includes the new RAN transmitting a requestfor a RRC release configuration or message when it is time to cause theUE to transition back to the INACTIVE state. In this signalingmechanism, the old RAN does not provide the RRC releasing configurationor message to the new RAN during a context retrieval procedure (as someconfigurations such as a periodic RAN-based Notification Area Update(RNAU) timer may not be accurate between UE and network if providedearly), but rather during a connection inactive procedure. During thecontext retrieval procedure, the old RAN transmits an indication not toperform a path switch to the new RAN. In this mechanism, the RRCreleasing configuration or message is provided upon request from the newRAN after UL or DL data transfer, when sending the UE back to INACTIVE.

FIG. 11 illustrates an example of a message exchange initiated by a RRCresume request containing a small data indication. The message exchangeinvolves multiple components including a UE, old RAN, new RAN, and UPF.The old RAN can serve as the anchor for the UE. In this example, the UEsends a small data indication to the old RAN via the new RAN, where theold RAN provides a RRC release configuration or message to the new RANvia a context retrieval procedure. The UE indicates its small dataintention during a resume procedure. As such, the UE, in theRRC_INACTIVE state, sends a RRC resume request message 1101 to the newRAN. The RRC resume request message 1101 includes a small dataindication.

The small data indication in message 1101 is communicated to the old RANvia a XnAP retrieve UE context request message 1102, which accordinglyincludes a small data indication. The old RAN can determine whether torelocate the anchor (meaning path switch is triggered from the new RANas the normal UE triggered transmission from INACTIVE to CONNECTEDscenario described in TS 38.300 Section 9.2.2.4.1) or not.

After receiving the XnAP retrieve UE context request message 1101, theold RAN can determine whether to relocate the anchor for the UE and senda XnAP retrieve UE context response message 1103 to the new RAN. If theold RAN decides not to relocate the anchor, the old RAN sends a XnAPretrieve UE context response message 1103. In some implementations, themessage 1103 includes a configuration necessary for the new RAN togenerate a RRC release message. The configuration information caninclude a Radio Network Temporary Identifier (RNTI) such as anInactive-RNTI (I-RNTI). The configuration information can include a RANNotification Area (RNA) configuration. This information can be used bythe new RAN to generate a RRC release message. In some otherimplementations, the message 1103 includes a RRC release messagegenerated by the old RAN. The new RAN can forward the release message asrequired to the UE. The message 1103 can include a key associated withgNB (e.g., KgNB) and a Next-Hop Chaining Counter parameter (NCC). Insome implementations, if the old RAN does not relocate the anchor (notshown), the old RAN responds with a XnAP retrieve UE context responsemessage as if the normal UE triggered transmission from INACTIVE toCONNECTED scenario described in TS 38.300 Section 9.2.2.4.1.

The new RAN sends a RRC resume message 1104 to the UE, which causes theUE to transition to the RRC_CONNECTED state and sends a RRC resumecomplete message 1105 to the new RAN. In some implementations, the newRAN sends a XnAP DL data forwarding address indication message 1106 tothe old RAN as legacy. The legacy already provides UL NG-U TNL at UPF tothe new RAN via the XnAP retrieve UE context response message 1103,which means that UL data does not have to go through the old RAN. Aftersending the RRC resume complete message 1105, the UE starts sending ULdata 1107 to the new RAN, which in turns forwards the UL data 1107 tothe UPF. The UPF may send DL data 1108 to the UE via the old RAN and thenew RAN. The old RAN can forward DL data 110 to the new RAN.

The new RAN can decide, when there is no more data from the UE, to causethe UE to transition back to the RRC_INACTIVE state. Based on makingthis decision, the new RAN sends a XnAP UE context release confirmmessage 1109 to the old RAN and sends a RRC release message 1110 to theUE.

The XnAP UE context release confirm message 1109 informs the old RANthat the UE is released and not to send DL data anymore. This message1109 can include information for migrating the UE context back to theanchor. For example, the new RAN may send the UE Context back to theanchor, if a configuration for the UE Context has been changed based onthe RRC resume message 1104. In some implementations, UP signaling canbe used where the new RAN sends the existing end-marker to the old RANover the forwarding TNL established, if configuration for the UE Contexthas not been changed based on the RRC resume message 1104.

The RRC release message 1110 sent to the UE causes the UE to transitionto the RRC_INACTIVE state. The RRC release message 1110 can be based onthe RRC Release message generated by the new RAN from the informationprovided from the old RAN or using RRC release message generated by theold RAN via message 1103, for which the new RAN applies securityprotection. The new RAN can apply security protection for a RRC releasemessage generated by the old RAN, because the security key has been usedby the new RAN (for message/data protection) and the old RAN cannot useit to protect a RRC release message generated by itself.

In some implementations, XnAP messages can be generated and transmittedbased on TS 38.423. In some implementations, the RRC resume requestmessage 1101 can include a “ResumeCause” information element to indicatethe resume cause. In some implementations, such as one based on 3GPP TS38.331, the resume cause codes can indicate emergency,highPriorityAccess, mt-Access, mo-Signaling, mo-Data, mo-VoiceCall,mo-VideoCall, mo-SMS, ma-Update, mps-PriorityAccess, mcs-PriorityAccess,or a mo-Small cause. Other types of causes are possible.

The XnAP retrieve UE context request message 1102 can be transmitted bythe new NG-RAN node to request the old NG-RAN node to transfer the UEContext to the new NG-RAN. This message 1102 can include one or moreinformation elements: message type, New NG-RAN node UE XnAP IDreference, UE Context ID, Integrity protection, New Cell Identifier, andRRC Resume Cause. Other or different types of information elements arepossible. In some implementations, the integrity protection IE for a RRCresume can include a ResumeMAC-I either contained in the RRCResumeRequest or the RRCResumeRequest1 message as defined in TS 38.331or the ShortResumeMAC-1 in the RRCConnection ResumeRequest message asdefined in TS 36.331. In some implementations, the new cell identifierIE for RRC resume can correspond to the targetCellIdentity within theVarResumeMAC-Input as specified in TS 38.331 or the cellIdentity withinthe VarShortINACTIVE-MAC-Input as specified in TS 36.331. In case of aRNA Update or Small Data Transfer, the RRC Resume Cause code containsthe cause value provided by the UE in the RRC ResumeRequest message, asdefined in TS 38.331, or in the RRCConnection ResumeRequest message, asdefined in TS 36.331. Other and different types of information elementsare possible.

The XnAP retrieve UE context response message 1103 can be sent by theold NG-RAN node to transfer the UE context to the new NG-RAN node. Insome implementations, the message includes a Message Type, New NG-RANnode UE XnAP ID reference, Old NG-RAN node UE XnAP ID reference,Globally Unique AMF ID (GUAMI), UE Context Information Retrieve UEContext Response, Trace Activation, Masked IMEISV, Location ReportingInformation, Criticality Diagnostics, and Old NG-RAN node To New NG-RANnode Release Container. In some implementations, the Release Containercan include the RRCRelease message as defined in TS 38.331, or theRRCConnectionRelease message as defined in TS 36.331. Other anddifferent types of information elements are possible.

In some implementations, the XnAP UE context release confirm message1109 can be sent by the new NG-RAN node to the old NG-RAN node toindicate that resources for the associated UE are released in the newNG-RAN node and to transfer the UE Context information back to the oldNG-RAN node. The UE context release confirm message 1109 can include thefollowing information elements: Message Type, New NG-RAN node UE XnAP IDreference, Old NG-RAN node UE XnAP ID reference, and UE ContextInformation UE Context Release Confirm. The New NG-RAN node UE XnAP IDreference can include a NG-RAN node UE XnAP ID which is allocated at thenew NG-RAN node. The Old NG-RAN node UE XnAP ID reference can include aNG-RAN node UE XnAP ID which is allocated at the old NG-RAN node. Otherand different types of information elements are possible.

FIG. 12 illustrates another example of a message exchange initiated by aRRC resume request containing a small data indication. The messageexchange involves multiple components including a UE, old RAN, new RAN,and UPF. The old RAN can serve as the anchor for the UE. In thisexample, the UE sends a small data indication to the old RAN via the newRAN, where the old RAN provides a no path switch indication. Further, aRRC release configuration or message is requested by the new RAN whensending UE back to INACTIVE. The UE indicates its small data intentionduring a resume procedure. As such, the UE, in the RRC_INACTIVE state,sends a RRC resume request message 1201 to the new RAN. The RRC resumerequest message 1201 includes a small data indication.

The small data indication in message 1201 is communicated to the old RANvia a XnAP retrieve UE context request message 1202, which accordinglyincludes the small data indication. The old RAN can determine whether torelocate the anchor. In this example, the old RAN decides not torelocate the anchor, and indicates to the new RAN not to trigger a pathswitch. The old RAN sends a XnAP retrieve UE context response message1203 that includes a no-path-switch indication. In some implementations,the message 1203 can include security parameters such as a KgNB and NCC.

The new RAN sends a RRC resume message 1204 to the UE. The resumemessage 1204 causes the UE to transition to the RRC_CONNECTED state andsend a RRC resume complete message 1205 to the new RAN. In someimplementations, the new RAN sends a XnAP DL data forwarding addressindication message 1206 to the old RAN as legacy signaling. In someimplementations, this legacy signaling provides a UL NG-U TNL at UPF tothe new RAN via the XnAP retrieve UE context response message 1203,which means that UL data does not have to flow through the old RAN.After sending the RRC resume complete message 1205, the UE startssending UL data 1207 to the new RAN, which in turns forwards the UL data1207 to the UPF. The UPF may send DL data 1208 to the UE via the old RANand the new RAN. The old RAN can forward the DL data to the new RAN viaa forwarding tunnel.

The new RAN can decide, when there is no more data from the UE, torelease the UE. As such, the new RAN sends a XnAP UE context releaserequest message 1209 to the old RAN. The XnAP UE context release requestmessage 1209 informs the old RAN that the UE is released and not to sendDL data anymore. This message 1209 can include information for migratingthe UE context back to the anchor. For example, the new RAN may send theUE Context back to the anchor if a configuration for the UE Context hasbeen changed based on the RRC resume message 1204.

After receiving the UE context release request message 1209, the old RANsends a UE context release response message 1210 to the new RAN torelease the resources for the associated UE in the new RAN. In someimplementations, the response message 1210 can include necessaryinformation (such as I-RNTI, RNA configuration, etc.) for the new RAN togenerate a RRC release message In some implementations, the responsemessage 1210 includes a RRC release message generated by the old RAN forwhich the new RAN applies security protection and forwards to the UE.

The new RAN can send a RRC release message 1211 to the UE to cause theUE to transition to the RRC_INACTIVE state. In some implementations, theRRC release message 1211 can be based on the RRC Release messagegenerated by the new RAN from the information provided from the old RAN.In some implementations, the RRC release message 1211 is a copy of a RRCrelease message generated by the old RAN which was included in the UEcontext release response message 1210.

In some implementations, the XnAP retrieve UE context response message1203 is sent by the old NG-RAN node to transfer the UE context to thenew NG-RAN node. The XnAP retrieve UE context response message caninclude the following information elements: Message Type, New NG-RANnode UE XnAP ID reference, Old NG-RAN node UE XnAP ID reference, GUAMI,UE Context Information Retrieve UE Context Response, Trace Activation,Masked IMEISV, Location Reporting Information, Criticality Diagnostics,and Path Switch Indication. The Path Switch Indication can indicate notto perform a path switch to the AMF, and can be a binary value (e.g., ayes value to perform a path switch and a no value to not perform a pathswitch).

In some implementations, the UE context release request message 1209 issent by the new NG-RAN node to the old NG-RAN node to request therelease of the associated UE in the new NG-RAN node and to transfer theUE Context information back to the old NG-RAN node. The UE contextrelease request message can include the following information elements:Message Type, New NG-RAN node UE XnAP ID reference, Old NG-RAN node UEXnAP ID reference, and a UE Context Information UE Context ReleaseRequest.

In some implementations, the UE context release response message 1210can be sent by the old NG-RAN node to the new NG-RAN node to release theresources for the associated UE in the new NG-RAN node. The UE contextrelease response message 1210 can include the following informationelements: Message Type, Old NG-RAN node UE XnAP ID reference, New NG-RANnode UE XnAP ID reference, UE Context ID, and Old NG-RAN node To NewNG-RAN node Release Container. In some implementations, the Old NG-RANnode To New NG-RAN node Release Container includes the RRCReleasemessage as defined in TS 38.331. In some implementations, the Old NG-RANnode To New NG-RAN node Release Container includes theRRCConnectionRelease message as defined in TS 36.331.

FIG. 13 illustrates a flowchart of an example of a process associatedwith the handling of a small data transmission by different nodes withina wireless communication system. This process can be performed byvarious types of RAN nodes such as the ones described herein. At 1305,the process includes receiving, by a first node, a resume request fromUE that is in an inactive state. The resume request can include a smalldata indication. The context information for the UE can reside at asecond node. In some implementations, the first node can be a gNB,whereas the second node can be an eNB. At 1310, the process includestransmitting, by the first node, a retrieve UE context request to thesecond node, the retrieve UE context request including the small dataindication. In some implementations, the first node is configured toforward the small data indication as a data field within the UE contextrequest.

At 1315, the process includes receiving, by the first node, a UE contextresponse from the second node. At 1320, the process includes receiving,by the first node, RRC release information from the second node. In someimplementations, the RRC release information can be encapsulated withina message transmitted by the second node. In some implementations, theUE context response includes the RRC release information such that thefirst node can generate a release message. In some implementations, theRRC release information is included in a UE context release messagewhich is exchanged between the nodes after the UL/DL transmissions arecompleted. Other types of messages are possible.

At 1325, the process includes transmitting, by the first node, a resumeresponse to the UE to cause the UE to switch to a connected state fromthe inactive state. At 1330, the process includes processing, by thefirst node, uplink data from the UE. Processing the uplink data from theUE can include receiving by the first node the uplink data from the UE;and forwarding the uplink data via the second node to a device thatprovides a UPF.

At 1335, the process transmits, by the first node, a release message tothe UE to cause the UE to switch to the inactive state from theconnected state. The release message can be based on the RRC releaseinformation received from the second node at 1320.

In some implementations, the UE context response includes RRC releaseinformation. In some implementations, the first node transmits a UEcontext release confirm message to the second node to stop data transferand to cause a UE context to transfer to the second node. In someimplementations, the RRC release information includes one or more RRCrelease configuration parameters, and the first node is configured togenerate the release message based on the one or more RRC releaseconfiguration parameters. In some implementations, the release messageis generated by the second node, forwarded to the first node, which inturns forwards the release message to the UE encapsulated in anothermessage.

In some implementations, the UE context response includes an indicationthat a path switch will not be perform. The first node can transmit a UEcontext release request to the second node; and receive a UE contextrelease response from the second node. The UE context release responsecan include the RRC release information. In some implementations, theRRC release information includes one or more RRC release configurationparameters, and the first node can generate the release message based onthe one or more RRC release configuration parameters. In someimplementations, the release message is generated by the second node,and the RRC release information includes the release message to betransmitted to the UE.

FIG. 14 illustrates a flowchart of an example of a process associatedwith a small data transmission request by a UE. At 1405, a UE, such asone described herein, can indicate a small data transmission requestupon a resumption from an INACTIVE state. A network component such as agNB can receive the small data transmission request and can cause the UEto start transmitting data by transmitting an instruction via a resumemessage. At 1410, the UE receives, in a RRC resume message, aninstruction to switch to a CONNECTED state from the INACTIVE state. At1415, the UE transitions to the CONNECTED state.

FIG. 15 illustrates a flowchart of an example of a process associatedwith the handling of a small data transmission by different nodes withina wireless communication system including a gNB and an eNB. At 1550, theprocess includes receiving, at a gNB, a small data transmission requestfrom the UE. At 1555, the process includes transmitting the small datatransmission request to the eNB. At 1560, the process includestransmitting an instruction for the UE to switch to a CONNECTED statefrom an INACTIVE state.

A node, such as an eNB or gNB, can be configured to inter-connect withother nodes via an Xn interface in 5GC. The node can be configured tosupport RRC state transitions for an UE in a RRC_INACTIVE state. In someimplementations, the UE is configured to indicate its small dataintention upon resumption. This indication can be transmitted to a newRAN node even though the UE may be anchored at an old RAN node. In someimplementations, the new RAN node is configured to forward the smalldata indication received from the UE to the old RAN node upon contextretrieval request. In some implementations, the old RAN node isconfigured to respond to the new RAN node with UE Context information,together with RRC release configuration parameters or RRC releasemessage generated by the old RAN node, or an indication not to performpath switch. In some implementations, the new RAN node is configured toinform the old RAN node that the UE is released and not to send DL dataanymore, with the UE Context information if necessary, when sending UEback to INACTIVE. In some implementations, the new RAN node isconfigured to send a request to the old RAN node to release the UE, withthe UE Context Information if necessary. In some implementations, theold RAN node responds to the new RAN node with RRC release configurationparameters or RRC release message generated by the old RAN node for thenew RAN node to send the UE back to INACTIVE.

In a wireless network including nodes such as an eNB, gNB, or both, awireless communication technique includes indicating, by a wirelessdevice, a small data transmission request upon resumption from anINACTIVE state; receiving, at the wireless device, an instruction toswitch to a CONNECTED state from the INACTIVE state, based on a RRCrelease message and a configuration; and transitioning, at the wirelessdevice, to the CONNECTED state. In some implementations, the techniqueincludes performing the small data transmission uplink to the gNB or theeNB. In some implementations, the technique includes receiving downlinkdata from the gNB or the eNB. In some implementations, the techniqueincludes receiving an instruction to resume the INACTIVE state.Indicating a small data transmission request can include transmittingthe small data transmission request to the gNB. In some implementations,the RRC release message is received from the gNB, and the configurationis provided by the eNB. In some implementations, the RRC release messageis generated by the eNB. In some implementations, the technique isperformed by a wireless device such as a UE or CIoT device.

A technique for a gNB in a wireless network including an eNB and a UEincludes receiving, at the gNB, a small data transmission request fromthe UE; transmitting the small data transmission request to the eNB; andtransmitting an instruction for the UE to switch to a CONNECTED statefrom an INACTIVE state. In some implementations, the technique includestransmitting a RRC release message and a configuration to the UE. Insome implementations, the technique includes receiving the small datatransmission uplink from the UE. In some implementations, the techniqueincludes transmitting data downlink to the UE. In some implementations,the technique includes transmitting an instruction to the UE to resumethe INACTIVE state. In some implementations, the technique includesapplying a security protection for a RRC Release message generated bythe eNB. In some implementations, the technique includes sending arequest to the eNB for the eNB to transfer a UE Context to the gNB. Insome implementations, the technique includes receiving the UE Contextfrom the eNB. In some implementations, the technique includes generatinga RRC release message for the UE. In some implementations, the techniqueincludes sending a request to the eNB to release the UE associated withthe gNB; and transferring UE Context information back to the eNB.

These and other techniques can be performed by an apparatus that isimplemented in or employed by one or more types of network components,user devices, or both. In some implementations, one or morenon-transitory computer-readable media comprising instructions to causean electronic device, upon execution of the instructions by one or moreprocessors of the electronic device, to perform one or more of thedescribed techniques. An apparatus can include one or more processorsand one or more computer-readable media comprising instructions that,when executed by the one or more processors, cause the one or moreprocessors to perform one or more of the described techniques.

The methods described here may be implemented in software, hardware, ora combination thereof, in different implementations. In addition, theorder of the blocks of the methods may be changed, and various elementsmay be added, reordered, combined, omitted, modified, and the like.Various modifications and changes may be made as would be obvious to aperson skilled in the art having the benefit of this disclosure. Thevarious implementations described here are meant to be illustrative andnot limiting. Many variations, modifications, additions, andimprovements are possible. Accordingly, plural instances may be providedfor components described here as a single instance. Boundaries betweenvarious components, operations and data stores are somewhat arbitrary,and particular operations are illustrated in the context of specificillustrative configurations. Other allocations of functionality areenvisioned and may fall within the scope of claims that follow. Finally,structures and functionality presented as discrete components in theexample configurations may be implemented as a combined structure orcomponent.

The methods described herein can be implemented in circuitry such as oneor more of: integrated circuit, logic circuit, a processor (shared,dedicated, or group) and/or memory (shared, dedicated, or group), anApplication Specific Integrated Circuit (ASIC), a field-programmabledevice (FPD) (e.g., a field-programmable gate array (FPGA), aprogrammable logic device (PLD), a complex PLD (CPLD), a high-capacityPLD (HCPLD), a structured ASIC, or a programmable SoC), digital signalprocessors (DSPs), or some combination thereof. In some implementations,the circuitry may execute one or more software or firmware programs toprovide at least some of the described functionality. The term“circuitry” may also refer to a combination of one or more hardwareelements (or a combination of circuits used in an electrical orelectronic system) with the program code used to carry out thefunctionality of that program code. In these embodiments, thecombination of hardware elements and program code may be referred to asa particular type of circuitry. Circuitry can also include radiocircuitry such as a transmitter, receiver, or a transceiver.

A number of implementations have been described. Nevertheless, it willbe understood that various modifications may be made. Elements of one ormore implementations may be combined, deleted, modified, or supplementedto form further implementations. As yet another example, the logic flowsdepicted in the figures do not require the particular order shown, orsequential order, to achieve desirable results. In addition, other stepsmay be provided, or steps may be eliminated, from the described flows,and other components may be added to, or removed from, the describedsystems. Accordingly, other implementations are within the scope of thefollowing claims.

1. A method comprising: receiving, by a first node, a resume requestfrom a user equipment (UE) that is in an inactive state, the resumerequest comprising a small data indication, wherein context informationfor the UE resides at a second node; transmitting, by the first node, aretrieve UE context request to the second node, the retrieve UE contextrequest comprising the small data indication; receiving, by the firstnode, a UE context response from the second node; receiving, by thefirst node, Radio Resource Control (RRC) release information from thesecond node; transmitting, by the first node, a resume response to theUE to cause the UE to switch to a connected state from the inactivestate; processing, by the first node, uplink data from the UE; andtransmitting, by the first node, a release message to the UE to causethe UE to switch to the inactive state from the connected state, whereinthe release message is based on the RRC release information receivedfrom the second node.
 2. The method of claim 1, wherein the UE contextresponse comprises the RRC release information.
 3. The method of claim2, comprising: transmitting, by the first node, a UE context releaseconfirm message to the second node to stop data transfer and to cause aUE context to transfer to the second node.
 4. The method of claim 2,wherein the RRC release information comprises one or more RRC releaseconfiguration parameters, and wherein the method comprises: generating,by the first node, the release message based on the one or more RRCrelease configuration parameters.
 5. The method of claim 2, wherein therelease message is generated by the second node, and wherein the RRCrelease information comprises the release message.
 6. The method ofclaim 1, wherein the UE context response comprises an indication that apath switch will not be performed.
 7. The method of claim 6, comprising:transmitting, by the first node, a UE context release request to thesecond node; and receiving a UE context release response from the secondnode, wherein the UE context release response comprises the RRC releaseinformation.
 8. The method of claim 7, wherein the RRC releaseinformation comprises one or more RRC release configuration parameters,and wherein the method comprises: generating, by the first node, therelease message based on the one or more RRC release configurationparameters.
 9. The method of claim 7, wherein the release message isgenerated by the second node, and wherein the RRC release informationcomprises the release message.
 10. The method of claim 1, wherein thefirst node is a gNodeB, and wherein the second node is an eNodeB. 11.The method of claim 1, comprising: transferring a UE context to thefirst node from the second node, wherein the UE context is transferredback to the second node after completion of a data transfer.
 12. Themethod of claim 1, wherein processing the uplink data from the UEcomprises: receiving the uplink data from the UE; and forwarding theuplink data to a device that provides a User Plane Function (UPF).
 13. Adevice comprising: circuitry to communicate with a first node; and aprocessor configured to perform operations comprising: transmitting,while in an inactive state, a resume request message to the first node,the resume request including a small data indication; receiving a resumeresponse containing an instruction to switch to a connected state fromthe inactive state; transitioning to the connected state in response tothe resume response; transmitting uplink data to the first node;receiving a release message containing an instruction to switch to theinactive state from the connected state; and transitioning to theinactive state in response to the release message.
 14. The device ofclaim 13, wherein the resume request message causes the second node totransfer device context information to the first node.
 15. A systemcomprising: one or more processors; circuitry, in a first node,configured to communicate with devices comprising a user equipment (UE);circuitry configured to communicate with a second node; and a memorystoring instructions that, when executed by the one or more processors,cause the one or more processors to perform operations comprising:receiving, by the first node, a resume request from a user equipment(UE) that is in an inactive state, the resume request comprising a smalldata indication, wherein context information for the UE resides at asecond node; transmitting, by the first node, a retrieve UE contextrequest to the second node, the retrieve UE context request comprisingthe small data indication; receiving, by the first node, a UE contextresponse from the second node; receiving, by the first node, RadioResource Control (RRC) release information from the second node;transmitting, by the first node, a resume response to the UE to causethe UE to switch to a connected state from the inactive state;processing, by the first node, uplink data from the UE; andtransmitting, by the first node, a release message to the UE to causethe UE to switch to the inactive state from the connected state, whereinthe release message is based on the RRC release information receivedfrom the second node.
 16. The system of claim 15, wherein the UE contextresponse comprises the RRC release information.
 17. The system of claim16, wherein the operations comprise: transmitting, by the first node, aUE context release confirm message to the second node to stop datatransfer and to cause a UE context to transfer to the second node. 18.The system of claim 16, wherein the RRC release information comprisesone or more RRC release configuration parameters, and wherein theoperations comprise generating, by the first node, the release messagebased on the one or more RRC release configuration parameters.
 19. Thesystem of claim 16, wherein the release message is generated by thesecond node, and wherein the RRC release information comprises therelease message.
 20. The system of claim 15, wherein the UE contextresponse comprises an indication that a path switch will not beperformed. 21-26. (canceled)